Ovarian, Testicular Cancers May Have Familial Association

Men with testicular cancer appeared more likely than those with other malignancies to have a mother with ovarian cancer, according to study results.

Researchers at Roswell Park Comprehensive Cancer Center investigated 31 families with a history of ovarian and testicular cancer from the Familial Ovarian Cancer Registry. The registry includes data for 2,636 families.

Investigators observed a statistically significant association between men with testicular cancer and mothers with ovarian cancer (OR=3.32; P=0.004).

In addition, sisters of men with testicular cancer appeared more likely to have ovarian cancer. Although no men with testicular cancer had a paternal grandmother with ovarian cancer, one-quarter of them had a maternal grandmother with ovarian cancer.

HemOnc Today spoke with John Lewis Etter, MPH, research associate at Roswell Park and MD/PhD student at University at Buffalo, and Kirsten Moysich, PhD, MS,distinguished professor of oncology in the department of cancer prevention and control and professor in the department of immunology at Roswell Park, about the findings and their potential implications.

Question: What prompted you to investigate th e association between testicular and ovarian cancers?

Moysich: Our group previously reported evidence for an X-linked ovarian cancer susceptibility gene variant that can be passed from father to daughter, and 12.5% of women with ovarian cancer in the Familial Ovarian Cancer Registry were carriers of this allele. Because of this, we were interested in investigating for an increased rate of cancers — specifically testicular cancers — among men in families from the registry.

Q: Can you elaborate on the sibling association between testicular and ovarian cancers, and what you think that association means?

Moysich: The observed sibling association provides further evidence for an association between familial ovarian and testicular cancers. At this time, further studies must be conducted to fully interpret what this association means.

Q: How about the fact that the association seemed to run through the maternal grandmother rather than the paternal grandmother?

Moysich: The observation that more maternal grandmothers of men with testicular cancer in the registry had ovarian cancer than paternal grandmothers is consistent with the hypothesis that the association between ovarian and testicular cancers is X-linked. A father cannot pass his X chromosome to his son; thus, a grandson can never inherit his paternal grandmother’s X-chromosome. If the association is indeed X-linked, we would expect to observe less ovarian cancer among paternal grandmothers of men with testicular cancer.

Q: What is the potential impact of these findings on clinical practice?

Etter: The results from this study provide preliminary evidence for an association between familial ovarian and testicular cancers. If these results are corroborated in future studies, they may help shape new guidelines for counseling male family members in families with multiple cases of ovarian cancer. Genetic studies also may offer insight into the etiology of these diseases, as well as targets for potential screening and therapies. Also, if substantiated, our results may translate into more aggressive screening for testicular cancer among young men with a strong family history of ovarian cancer.

Q: Where will the research go next?

Etter: We have begun targeted enrollment of families with cases of both ovarian and testicular cancer into the Familial Ovarian Cancer Registry. We will conduct further studies to better understand the genetic basis of the observed association with the goal of identifying a gene target for screening and therapy. Also, what is important about this work is that we are the first to uncover this link because we oversee this unique registry that collects detailed cancer history information that is not captured in any traditional cancer population science study. – by Rob Volansky

References

Etter JL, et al. Cancer Epidemiol. 2018;doi:10.1016/j.canep.2018.02.005.

To read this article by Healio, please click here.

Multi-epitope T-cell Vaccine Shows Promise in Ovarian, Breast Cancer

Clinicians in the not-too-distant future may have something new to offer women with breast cancer and ovarian cancer in whom initial therapy fails to yield a response. Writing in Clinical Cancer Research, investigators at the Mayo Clinic report that a vaccine is showing benefit in combating ovarian cancer in women who have suffered recurrence following successful platinum-based therapy.

In a phase I study, patients were immunized over a 6-month period following pretreatment with cyclophosphamide, and then monitored for an additional 12 months. Investigators found that the TPIV200 vaccine generated robust immune responses and was well tolerated by all patients. There was only one Grade 3 adverse event reported in the study, and it was related to a local ulceration that resolved.

TPIV200 is a multi-epitope T-cell vaccine that targets folate receptor alpha (FRa). It is comprised of a mixture of five folate receptor alpha peptides. “These are mixed with an adjuvant or immune-stimulant (GM-CSF [granulocyte-macrophage colony-stimulating factor]) to give the drug product which is injected into patients. The mechanism of action is to broadly stimulate T cells to attack tumor cells (ovarian and triple-negative breast) that overexpress the folate receptor alpha protein. The peptides were chosen to cover about 90% of the population,” said Richard Kenney, MD, Acting Chief Medical Officer for TapImmune, Jacksonville, Florida.

The study showed that generation of T-cell immunity following immunization was robust and long-lasting. Analysis showed 91% of patients had an antigen-specific response, with 89% of those patients responding to multiple epitopes included in TPIV200. The researchers reported that T-cell responses developed slowly over the course of vaccination. In this initial study, the median time to maximal immunity was 5 months. Ovarian cancer patients, who entered the study upon their first remission (n = 10) had a median progression-free survival (PFS) of 528 days (95% CI, 110–548 days).

TapImmune, Inc., which is developing this vaccine in partnership with the Mayo Clinic and Sloan-Kettering Cancer Center, believes this vaccine product could eventually help a significant number of women who now have few treatment options. Peter Hoang, President and CEO of TapImmune, said all patients remained alive at last follow-up, at least 2 years following initiation of immunization. He said the observed median PFS of 528 days is an interesting result because the historical data with patients receiving standard-of-care therapy in this setting show a median PFS of 313 days.

The current phase I study enrolled women with histologically confirmed stage II–III breast cancer or stage II–IV ovarian (including primary peritoneal and fallopian tube) cancer who had completed systematic therapy (except for hormonal treatment or bisphosphonates) at least 90 days prior to registration. All the women were without evidence of disease at time of enrollment. Dr. Kenny noted that women in first remission are likely to have healthier immune systems, having not gone through multiple rounds of chemotherapy. He said this may better position them to benefit from vaccination with TPIV200.

To read this full article on CancerNetwork.com, please click here.

Endometriosis Raises Risk of Ovarian Cancer but Not Other Gynecological Cancers, Study Suggests

Women with endometriosis are at an increased risk of developing ovarian cancer, but not cervical cancer or other cancers affecting the female reproductive organs, a nationwide Finnish study suggests.

The study, “Risk of Gynecologic Cancer According to the Type of Endometriosis,” was published in the journal Obstetrics & Gynecology.

Several studies have suggested that endometriosis and cancer share common features, such as increased cell proliferation, tissue invasion, and decreased cell death.

Endometriosis tissue is also known to produce several hormones and other molecules that help sustain an inflammatory state, factors that can contribute to cancer development and progression.

The association between endometriosis and cancer has been explored in several studies that have shown that endometriosis is linked to a higher risk of ovarian cancer. However, the association with other types of gynecological cancer is unclear.

A research team reviewed the clinical records from the Finnish Hospital Discharge Register of 49,933 women surgically diagnosed with endometriosis between 1987 and 2012. The type of lesions they had were classified, according to the affected tissues, as ovarian (23,210 cases), peritoneal (20,187 cases), and deep infiltrating (2,372 cases) endometriosis. Information on the incidence of gynecological cancers was obtained from the Finnish Cancer Registry.

In line with previous data, the researchers found that endometriosis was associated with an increased risk of ovarian cancer. In particular, these women were found to have a 3.12 times higher incidence of the endometrioid type of ovarian cancer and a 5.17 times higher incidence of the clear cell type than the general female population.

This association was found to be stronger in women with ovarian endometriosis, who were found to have a 4.72 times increased incidence of the endometrioid type and 10.1 times increased incidence of clear cell ovarian cancer. Peritoneal endometriosis was also associated with a twofold increased risk for endometrioid ovarian cancer, while no association was found with deep infiltrating endometriosis.

The risk of cervical, endometrial, or other uterine cancers was no different than that reported in the general population. Endometriosis was also not associated with a higher risk for cancers in other female genital organs, such as the vulva or vagina.

“Acknowledging these risks is important when planning long-term management of women with endometriosis,” the researchers said.

“The excess risk of ovarian cancer among women with ovarian endometriosis translates into two excess cases per 1,000 patients followed for 10 years,” they wrote.

To read this entire article by Endometriosis News, please click here.

Fully Reprogrammed Virus Offers New Hope As Cancer Treatment

A cancer treatment that can completely destroy cancer cells without affecting healthy cells could soon be a possibility, thanks to research led by Cardiff University.

The team of researchers has successfully ‘trained’ a respiratory virus to recognise ovarian cancer and completely destroy it without infecting other cells.

The reprogrammed virus could also be used to treat other cancers such as breast, pancreatic, lung and oral.

Dr. Alan Parker from Cardiff University’s School of Medicine said: “Reprogrammed viruses are already being used in gene therapy procedures to treat a range of diseases, demonstrating they can be trained from being life-threatening into potentially lifesaving agents.

“In cancer treatment, up until now, reprogramed viruses have not been able to selectively recognise only the cancer cells and would also infect healthy cells, resulting in unwanted side effects.

“We’ve taken a common, well-studied virus and completely redesigned it so that it can no longer attach to non-cancerous cells but instead seeks out a specific marker protein called αvβ6 integrin, which is unique to certain cancer cells, allowing it to invade them.

“In this case we introduced the reprogrammed virus to ovarian cancer which it successfully identified and destroyed.

“This is an exciting advance, offering real potential for patients with a variety of cancers.”

Once the virus enters the cancer cell it uses the cell’s machinery to replicate, producing many thousands of copies of itself, prior to bursting the cell and thereby destroying it in the process. The newly released viral copies can then bind and infect neighbouring cancer cells and repeat the same cycle, eventually removing the tumour mass altogether. The virus also activates the body’s natural immune system, helping it to recognise and destroy the malignant cells.

The reprogrammed virus is from a group of respiratory viruses called adenoviruses. The advantage of using these viruses is that they are relatively easy to manipulate and have already been safely used in cancer treatment.

The technique used to reprogramme the virus to identify the protein common to ovarian, breast, pancreatic, lung and oral cancers could also be used to manipulate it so that it would recognise proteins common to other groups of cancers.

Additional refinement to the viral DNA could also allow the virus to produce anticancer drugs, such as antibodies, during the process of infecting cancer cells. This effectively turns the cancer into a factory producing drugs that will cause its own destruction.

The research was carried out in a laboratory, using mice with ovarian cancer, and has not yet reached clinical trials. The next step is to test the technique with other cancers, with a view to starting clinical trials in five years’ time.

Dr. Catherine Pickworth from Cancer Research UK said: “It’s encouraging to see that this virus, which has been modified to recognise markers on cancer cells, has the ability to infect and kill ovarian cancer cells in the lab. Viruses are nature’s nanotechnology and harnessing their ability to hijack cells is an area of growing interest in cancer research. The next step will be more research to see if this could be a safe and effective strategy to use in people.”

The paper “Ad5NULL-A20 – a tropism-modified, αvβ6 integrin-selective oncolytic adenovirus for epithelial ovarian cancer therapies” is published in Clinical Cancer Research.

To read this entire article by Medical Xpress, please click here.

Complete Resection Possible in Recurrent, Low-Volume Ovarian Cancer

A long treatment-free interval (TFI) prior to first recurrence of epithelial ovarian cancer and three lesions or fewer on imaging bode well for complete tumor resection after secondary cytoreductive surgery, a Norwegian registry-based study showed.

Among 397 selected patients with recurrent, platinum-sensitive epithelial ovarian cancer, those with a complete resection who were treated with platinum-based chemotherapy had their cancer recurrence delayed for 2 years and had a median overall survival of at least 6 years, reported Witold Szczesny, MD, of the Cancer Registry of Norway, Oslo, and colleagues.

“The role of secondary surgery in recurrent ovarian cancer treatment has not been clearly defined, and conclusive evidence is lacking,” the authors wrote in Acta Obstetricia et Gynecologica Scandinavica. “Our results suggest that a long treatment-free interval and non-disseminated lesions (three or fewer lesions) on radiological images could be useful predictors for complete resection at secondary cytoreductive surgery.”

The retrospective study showed that in 75 patients who underwent secondary cytoreductive surgery plus platinum-based chemotherapy, complete resection was achieved in 60 (80%). Progression-free survival (hazard ratio [HR] 0.45) and overall survival (HR 0.50) were improved in this group compared with 322 patients who received platinum-based chemotherapy alone. A survival benefit was seen only in patients with no residuals at secondary cytoreductive surgery.

Christina S. Chu, MD, of Fox Chase Cancer Center in Philadelphia, told MedPage Todaythat many previous retrospective studies have looked at this question.

“Their findings basically align with what has been seen in the past: good candidates selected for secondary debulking do better than those who have more extensive disease who are not candidates for debulking,” said Chu, who was not involved with the study.

“Patients with low volume recurrences that are easy to resect get surgery,” she said, pointing out that the biases inherent in retrospective studies are difficult to overcome. “Those with more extensive disease get chemo alone.”

Accrual has been completed for the definitive phase III Gynecologic Oncology Group (GOG) 2013 trial. “This will be a much better study,” Chu predicted. GOG 2013 randomized patients with recurrent platinum-sensitive disease to debulking or no debunking, and then chemotherapy.

In the U.S., candidates for secondary debunking in epithelial ovarian cancer generally include those with limited platinum-sensitive recurrence believed to be completely resectable, said Chu. “I would argue that all patients with ovarian cancer/recurrent ovarian cancer should be seen by a gynecologic oncologist,” she added.

For the study, the Szczesny’s group examined data for 397 patients with a primary diagnosis of FIGO (International Federation of Gynecology and Obstetrics) stage I-IV epithelial ovarian cancer who had been documented in the Cancer Registry of Norway from 2002 to 2012.

Participants had received primary surgery with no residual disease, followed by platinum-based chemotherapy. First recurrence took place 6 or more months after completion of primary chemotherapy, and patients underwent secondary treatment with either secondary cytoreductive surgery and platinum-based chemotherapy or platinum-based chemotherapy alone.

Most of the patients had FIGO stages III disease: 48% of patients (36) in the secondary cytoreductive surgery plus chemotherapy group compared with 56% (179) in the chemotherapy-alone group.

Fifty-five patients (73%) patients in the secondary cytoreductive surgery plus chemotherapy group had serous histology, compared with 228 (71%) in the chemotherapy-alone group (P=0.3).

In the secondary cytoreductive surgery plus chemotherapy group, 48 patients (64%) had a TFI >24 months compared with 155 patients (48%) in the chemotherapy group (P=0.04).

At recurrence, 19 patients (25%) in the secondary cytoreductive surgery plus chemotherapy group had more than three lesions on radiological imaging compared with 143 patients (44%) in the chemotherapy-only group (P=0.001).

Whether improved overall survival in the surgery plus chemotherapy group was treatment or biology related remains unknown, the researchers said. However, other studies have provided evidence of a possible association between longer TFI and improved progression-free survival, they pointed out.

Analyses revealed a higher HR for mucinous, clear cell and non-classified adenocarcinomas, a finding that is also in keeping with earlier studies, the researchers said. “This finding could be explained by more aggressive biological activity of these tumors.”

The study was limited by the small number of identified confounders, they said, noting that TFI was used as a confounding variable to match the treatment groups.

To read this entire article in MedPageToday.com, please click here.

New Options Now Available For Ovarian Cancer

Ovarian cancer is estimated to affect more than 22,000 women each year and is the fifth leading cause of cancer deaths among women, according to American Cancer Society.

Unlike other gynecologic cancers, there are no screening tests for ovarian cancer. While some women diagnosed with ovarian cancer have elevated levels of the CA 125 protein, the associated blood test is not accurate enough for ovarian cancer screening, as many noncancerous conditions can increase the CA 125 level.

Ovarian cancer is hard to detect in its early stages due to its vague symptoms. Women may experience constipation, bloating, early satiety after eating and back pain. While ovarian cancer tends to occur in post-menopausal women, anyone can be at risk. A number of factors, including smoking, endometriosis, polycystic ovary disease and obesity, can raise a woman’s risk for the disease.

About 20 percent of all ovarian cancers are caused by a genetic mutation. The genes most likely to increase the risk of ovarian cancer are BRCA1 and BRCA2. These genes also affect a woman’s risk of breast cancer. Genetic mutations that cause Lynch syndrome, an inherited condition associated with colon cancer, also raise a woman’s risk of ovarian cancer.

Over the past two decades, there were few options to treat ovarian cancer other than surgery and chemotherapy. And recurrence of the disease was common.

“Ovarian cancer, thankfully, does respond really nicely to surgery and chemotherapy. But unfortunately, in roughly 70 percent of patients, we do see recurrence,” says Dr. Andrea Wahner Hendrickson, a Mayo Clinic oncologist.

But thanks to research by Wahner Hendrickson and her colleagues, patients now have additional – and sometimes more effective – options for treatment, including individualized medical therapy and immunotherapy.

Currently, there are more than 1,350 clinical trials for ovarian cancer, including a vaccine trial aimed at preventing recurrence.

Since not all tumors respond to every treatment, Dr. Wahner Hendrickson recommends all ovarian cancer patients undergo genetic testing to see which therapy might work best or them.

“Thanks to the innovations, I think there’s a lot of promise and hope in the treatment of ovarian cancer,” says Wahner Hendrickson.

She encourages women of all ages to see their physician if they experience abnormal signs or symptoms.

To read the full article by Albuquerque Journal, please click here.

Trabectedin Plus PLD Shows Benefit in Real-Life Ovarian Cancer Setting

The combination of trabectedin and pegylated liposomal doxorubicin (PLD) offered clinical benefit and was reasonably well tolerated in a real-life setting of patients with previously treated platinum-sensitive recurrent ovarian cancer, according to a new study.

“Thus far no prospective, non-interventional study with trabectedin plus PLD had been performed in a routine clinical setting, with a more diverse patient population with platinum-sensitive recurrent ovarian cancer than that recruited in clinical trials,” wrote study authors led by Ingo B. Runnebaum, MD, of Jena University Hospital in Germany. “Such an observational study can provide useful insights of the real-world toxicity, efficacy, and management of patients receiving trabectedin plus PLD.”

The OVA-YOND trial included 77 patients with platinum-sensitive recurrent ovarian cancer who had been previously treated with at least one platinum-containing regimen. Patients received a median of 6 cycles of trabectedin plus PLD; 50.6% received 6 or more cycles. The median treatment duration was 4.2 months, and 88.3% of patients were treated on an outpatient basis. The results of the analysis were published in the Journal of Cancer Research and Clinical Oncology.

Five patients (6.5%) achieved a complete response to the treatment, and another 19 patients (24.7%) achieved a partial response, for an overall response rate of 31.2% and a median duration of response of 6.25 months. Another 16 patients had disease stabilization, for a disease control rate of 52.0%.

The median progression-free survival was 6.3 months, and 77.2% of patients were free from progression at 3 months; at 6 months, that rate was 50.3%. The median time to progression was 7.3 months. The median overall survival was 16.4 months, and 58.3% of patients were alive 12 months after treatment.

Just over half of the cohort (57.1%) had at least one trabectedin-related adverse event (AE) of any grade. The most common grade 3/4 AEs included leukopenia (18.2% of patients), neutropenia (15.6%), and thrombocytopenia (9.1%).

With regard to PLD-related AEs, 63.6% of the study population experienced at least one AE of any grade. The most common grade 3/4 AEs related to PLD again included neutropenia (18.2%), leukopenia (15.6%), and thrombocytopenia (10.4%). There were no deaths attributed to drug-related AEs.

“The findings of this non-interventional, prospective real-life study consistently support that trabectedin plus PLD confers clinically meaningful long-term benefits to pretreated patients with platinum-sensitive recurrent ovarian cancer,” the authors concluded. “Large randomized trials are warranted to show that platinum-free combinations in platinum-sensitive disease may effectively allow patients’ recovery from previous platinum-associated adverse effects with similar or improved oncological outcome.”

To read this entire article in CancerNetwork.com, please click here.

Scientists Identify Why Some People May Be Resistant To PARP Inhibitor Drugs

A team of scientists from the Institute of Cancer Research in London has identified DNA mutations which makes cancer cells resistant to a new class of drugs called PARP inhibitors, used for the treatment of breast and ovarian cancers.

The research published today in Nature Communications used the CRISPR/Cas9 gene editing system to artificially make different DNA mutations in the PARP1 gene, then testing the effect of these mutations on the sensitivity of cancer cells to PARP inhibitors. These included olaparib (marketed by AstraZeneca as Lynparza), which achieved FDA approval for treating a particular type of breast cancer in January of this year after approval for some types of ovarian cancer last year and Pfizer’s talazoparib, which has shown promising results in recent clinical trials.

Lead author of the study, Dr Stephen Pettitt, Staff Scientist in Cancer Genomics at The Institute of Cancer Research, London, said: “Our study has discovered one of the reasons why resistance to PARP inhibitors such as olaparib might occur. Testing for the mutations we have identified could offer even more personalized treatment for women with breast and ovarian cancer, by allowing doctors to judge whether and for how long olaparib should be used.”

PARP1 is part of a family of proteins which are responsible for repairing damaged DNA. In healthy cells, this is a good thing but in cancer cells, especially with patients who have mutations in other DNA repair genes, the PARP system may actually help the cell survive. By using PARP inhibitors, this process can be blocked, leading to the death of cancer cells.

PARP inhibitors are particularly effective in people with inherited DNA mutations in BRCA genes, the hereditary disorder that means women have a much-increased risk of breast and ovarian cancers, which hit the headlines a few years ago after Angelina Jolie had a preventative mastectomy.

The researchers stress more work is needed to look for actual PARP1 mutations found in human patients rather than made artificially in the lab, but in the future, they hope that testing for these DNA mutations can help guide clinicians to prescribe the best treatment for patients.

Baroness Delyth Morgan, Chief Executive at Breast Cancer Now, which helped to fund the study, said: Resistance to breast cancer drugs is a major hurdle that we must overcome if we are to stop women dying from this devastating disease. Studies like this could help take us a step closer to an even more personalized approach to treating the disease.’

To read this full article on FORBES, please click here.

Is Adjuvant Chemo Warranted In Stage I Ovarian Clear Cell Carcinoma?

In patients with stage I ovarian clear cell carcinoma, the use of adjuvant chemotherapy was associated with superior overall survival (OS), according to results of a large, retrospective cohort study.

The finding, published in Gynecologic Oncology, provides further evidence that adjuvant chemotherapy may provide a survival advantage for patients with this relatively common epithelial ovarian cancer subtype.

However, not all data to date point toward a benefit of adjuvant chemotherapy. “Its utility has yet to be established, especially for patients with stage IA disease,” wrote Dimitrios Nasioudis, MD, and his coauthors in the department of obstetrics and gynecology, Hospital of the University of Pennsylvania, Philadelphia.

In one recent large population-based study, chemotherapy was not associated with superior OS in patients with stage I disease, whereas two smaller retrospective studies suggested that chemotherapy may improve progression-free survival in that setting, noted Dr. Nasioudis and his colleagues.

Their study included data on 2,325 patients in the National Cancer Data Base diagnosed with stage I ovarian clear cell carcinoma between 2004 and 2014. That is the largest cohort of patients with stage I ovarian clear cell carcinoma with adequate staging reported to date in the medical literature, the investigators noted.

The rate of OS at 5 years was 89.2% for patients receiving adjuvant chemotherapy, versus 82.6% for those who did not (P less than .001). Furthermore, adjuvant chemotherapy was associated with improved OS after the researchers controlled for medical comorbidities, age, race, disease substage, and hospital type (hazard ratio, 0.59; 95% confidence interval, 0.45-0.78).

When the researchers looked at disease substage, women with stage IA or IB disease had superior OS with chemotherapy versus no chemotherapy, while in women with stage IC disease, there was a trend toward better OS with chemotherapy that did not reach statistical significance.

“The administration of adjuvant chemotherapy was associated with a survival benefit, even for those with stage IA disease,” the researchers wrote.

Ovarian clear cell carcinoma is the third most common subtype of epithelial ovarian carcinoma, accounting for up to 25% of new diagnoses, they said. Current U.S. and European clinical practice guidelines recommend adjuvant chemotherapy for all women with stage I disease because of a high risk of relapse associated with this subtype.

Observation could be acceptable for patients with surgical stage IA disease, in light of excellent survival rates, the Gynecologic Cancer Intergroup has suggested.

While the present study suggests a survival benefit associated with chemotherapy in stage I ovarian clear cell carcinoma, the investigators had no information on morbidity, cost, or quality-of-life impacts associated with treatment, which limit the findings.

“International collaboration, such as the creation of ovarian clear cell carcinoma registry, is greatly needed to further elucidate the optimal management of those patients,” they wrote.

Dr. Nasioudis and his coauthors had no conflicts of interest to report.

To read this full article on mdedge.com, please click here.

National Survey Examines Oncologists’ Practices, Beliefs on Medical Marijuana Use

Data from a new survey show that as many as 80% of oncologists have discussed medical marijuana use with their patients. According to the authors, this is the first nationally representative survey to examine oncologists’ practices and beliefs on the subject since the implementation of state medical marijuana laws. The research was published by Braun et al in the Journal of Clinical Oncology.

“Our study shows that medical marijuana is a salient topic in cancer care today, and the majority of oncologists think it may have utility for certain patients,” said study author Ilana Braun, MD, Chief of the Division of Adult Psychosocial Oncology at the Dana-Farber Cancer Institute. “While this topic is common, however, data on medical marijuana use is less so. We need to bridge this gap so oncologists have the unbiased information they need to assist with decision-making related to medical marijuana use.”

California enacted the United States’ first medical marijuana law in 1996, and today, its use is legal in more than 30 states, almost all of which list cancer as a qualifying condition. In the 22 intervening years, however, no randomized clinical trial has investigated the utility of whole-plant medical marijuana to alleviate symptoms such as pain, insomnia, or nausea and vomiting in patients with cancer.

Many studies have explored the use of pharmaceutical cannabinoids—highly refined, quality-controlled products consisting of one or two active ingredients and available through a pharmacy. Nonpharmaceutical medical marijuana, however, is often whole-plant, containing hundreds of active ingredients, and thus cannot easily be compared to pharmaceutical cannabinoids.

Recent clinical practice guidelines from ASCO recognize knowledge gaps about medical marijuana use in oncology. The guidelines note insufficient evidence to recommend medical marijuana for the initial management of chronic pain in cancer survivors, although evidence suggests it is worthy of consideration as an adjuvant analgesic and for managing pain conditions that are difficult to treat. Evidence also remains insufficient to recommend medical marijuana for the prevention of nausea and vomiting in patients with cancer who receive chemotherapy or radiation therapy.

About the Study

Researchers mailed a survey to 400 practicing oncologists in the United States, randomly selected from a national database of board-certified medical oncologists. Of the 237 participants who responded, more than half (55%) practice in states where medical marijuana is legal.

The survey asked oncologists about their discussions with patients, recommendations they provided, and their knowledge of medical marijuana. Respondents were also asked about their views on the effectiveness of medical marijuana for cancer-related symptoms such as pain, nausea and vomiting, depression, anxiety, poor appetite, poor sleep, and general coping, as well as its risks compared with other treatments.

Key Findings

Researchers found that most oncologists surveyed had encountered questions about medical marijuana, and many expressed research and education needs to better inform the care they provide to patients with cancer. Specifically:

• Physician discussions: 80% reported discussing medical marijuana with patients, and 78% reported these conversations were most frequently initiated by patients and their families.
• Education: Less than 30% felt knowledgeable enough about medical marijuana to make recommendations.
• Recommendations: Nearly half (46%) recommended medical marijuana use to patients in the past year.
• Beliefs on potential benefit: More than two-thirds (67%) believed medical marijuana to be a helpful treatment for alleviating pain when used together with standard therapies, and a majority viewed it as presenting a lower risk than opioids for overdose death (75%) and addiction (52%). Nearly two-thirds (65%) also viewed it as equally or more effective than standard treatments for poor appetite and extreme weight loss. When evaluating its effectiveness for other conditions, however, many oncologists responded, “I do not know,” from 29% for nausea and vomiting to 45% for poor sleep.

The study showed that the following factors contributed to significant differences in oncologists’ practices regarding medical marijuana:

• Geographic location: Oncologists practicing in the Western United States were more likely to have discussed (95%) or recommended (84%) medical marijuana, and oncologists practicing in the South were least likely (69% and 35%, respectively).
• Type of practice: Respondents practicing outside a hospital setting were more likely to recommend medical marijuana than hospital-based oncologists (54% vs 35%).
• Size of practice: Oncologists who saw the most patients each week were more likely to have discussed medical marijuana than those who saw the fewest patients (89% vs 70%).

Next Steps

In the article, researchers call for clinical trials to address these gaps in knowledge regarding medical marijuana use. “I think we need to carry out comparative effectiveness studies of medical marijuana to clarify its role,” said Dr. Braun. “We also need to extend our survey to other specialties and to patients with cancer.”

This study received funding from the Hans and Mavis Lopater Foundation.

To read this entire post on The ASCO Post, please click here.