'Risky': Prostate Radiation, Second Cancers Linked

“External-beam radiation for prostate cancer appears to be tied to the development of secondary cancers.

“Compared with other prostate cancer treatment types, the use of radiotherapy was associated with an increased risk for additional cancers in the lower half of the torso, according to a meta-analysis of 21 studies.

“Specifically, there was an increased risk for cancers of the bladder (adjusted hazard ratio [HR], 1.67; 95% confidence interval [CI], 1.55 – 1.80), colorectum (three studies) (HR, 1.79; 95% CI, 1.34 – 2.38), and rectum (HR, 1.79; 95% CI, 1.34 – 2.38).”

A Third of Breast Cancer Patients Concerned About Genetic Risk

“A new study from the University of Michigan Comprehensive Cancer Center finds that many women diagnosed with breast cancer are concerned about the genetic risk of developing other cancers themselves or of a loved one developing cancer.

“Overall, 35 percent of women with breast cancer expressed a strong desire for genetic testing, but 43 percent of those women did not have a relevant discussion with a health care professional. The study also found that racial minority patients with a strong desire for testing were less likely than white patients to discuss it with a professional, even though studies show that minority patients are not at lower risk for these mutations.

” ‘Our findings suggest a marked unmet need for discussion about genetic risk,’ says study author Reshma Jagsi, M.D., D.Phil., associate professor of radiation oncology at the University of Michigan Medical School.

“About 5 percent to 10 percent of breast cancer patients have an inherited genetic mutation that drives their cancer. Many of the women who reported interest in genetic testing were at low risk of having a mutation and doctors would not typically discuss genetic risk with them.”

Risk for Leukemia after Treatment for Early-Stage Breast Cancer Higher than Reported

“The risk of developing leukemia after radiation therapy or chemotherapy for early stage breast cancer remains very small, but it is twice as high as previously reported, according to results of a new study led by researchers at the Johns Hopkins Kimmel Cancer Center.

“The study team reviewed data on 20,063 breast cancer patients treated at eight U.S. cancer centers between 1998 and 2007 whose cancer recurrence and secondary cancer rates were recorded in a database kept by the National Comprehensive Cancer Network. In that group, 50 patients had developed some form of leukemia within 10 years after radiation therapy, chemotherapy or a combination of the two. That translates to roughly a cumulative risk of 0.5 percent.

“Data from earlier randomized clinical trials, which typically include just a few hundred patients, found that about 0.25 percent of breast cancer patients develop leukemia as a late effect of chemotherapy, says Judith Karp, M.D., professor emerita of oncology at the Johns Hopkins University School of Medicine, who retired in 2013 as director of the Kimmel Cancer Center’s Leukemia Program.”

NSCLC Patients Who Never Smoked or Who Quit Smoking Have Lower Risk of Developing Secondary Cancers

“Non-small cell lung cancer (NSCLC) survivors who never smoked or who are former smokers at the time of diagnosis have a lower risk of developing secondary primary lung cancers (SPLC) compared to those who are current smokers, suggesting that increased tobacco exposure is associated with a higher risk of SPLC, according to research presented today at the American Society for Radiation Oncology’s (ASTRO’s) 56th Annual Meeting.

“The analysis studied the association between patients‘ smoking histories and their risks of developing SPLC, which is defined as a new lung cancer unrelated to the initial tumor based on histology and location in the lung.

“The study analyzed 1,484 patients (372 current smokers, 1,014 former smokers and 98 never smokers) who underwent surgery, with or without adjuvant chemotherapy or radiation therapy, for stage I-IIIA NSCLC at Duke University Medical Center between 1995 and 2008. Baseline covariates and oncologic outcomes including local control (LC), development of distant metastases (DM), overall survival (OS) and rates of SPLC were assessed. SPLC were distinguished from metastases based on histologic evaluation supplemented with clinical presentation, including the anatomic site and chronological onset of diagnosis. Hazard ratios (HR) were calculated with 95 percent confidence intervals, and multivariate analysis (MVA) were performed using a Cox regression model.

“The study found that five years after the initial diagnosis, current smokers were more likely to develop SPLC. The five-year incidence of SPLC was 13 percent for current smokers, seven percent for former smokers, and zero percent for patients who had never smoked. In the follow-up period, only one patient who had never smoked developed an SPLC, seven years after surgery for the first cancer.”

Radiation for Prostate Cancer Linked to Secondary Cancers

“Among men treated for prostate cancer, those who received radiation therapy were more likely to develop bladder or rectal cancer, according to a new study from the University of Michigan Comprehensive Cancer Center.

“ ‘Overall the incidence of these cancers is low. But when men have received radiation treatments, it’s important to evaluate carefully any symptoms that could be a sign of bladder or rectal cancer,’ said senior study author Kathleen Cooney, professor of hematology/oncology and urology at the U-M Medical School.”

Paradoxical Oncogenesis—The Long-Term Effects of BRAF Inhibition in Melanoma

The clinical benefits of BRAF inhibition in patients with advanced-stage BRAF-mutant melanoma are now well established. Although the emergence of cutaneous squamous-cell carcinomas (SCCs) and secondary melanomas in patients on BRAF-inhibitor therapy have been well described, reports are emerging of additional secondary premalignant and malignant events, including RAS-mutant leukaemia, the metastatic recurrence of RAS-mutant colorectal cancer and the development of gastric and colonic polyps.”