Patients with metastatic renal cell carcinoma who transitioned to a modified 2/1 schedule of sunitinib experience an improved safety profile compared with that observed during the initial 4/2 schedule, a new study published online ahead of print in the journal Annals of Oncology has shown.

Patients receiving first-line sunitinib to treat metastatic renal cell carcinoma typically receive 4 weeks of treatment followed by 2 weeks off, but that schedule is often associated with relevant toxicities and related dose reductions. Therefore, researchers sought to evaluate the safety profile of an alternative schedule, 2 weeks on and 1 week off.

For the study, researchers retrospectively analyzed data from 249 patients with metastatic renal cell carcinoma who received first-line treatment with sunitinib.

Of those, 208 initiated sunitinib on the 4/2 schedule and then transitioned to the 2/1 schedule due to toxicity and 41 patients started with sunitinib on the 2/1 schedule.

Researchers compared the safety of those patients with 211 patients treated with the 4/2 schedule at another institution.

Results showed that among those who started on the 4/2 schedule and switched to the 2/1 schedule, the overall incidence of grade 3 or higher toxicities was significantly reduced from 45.7% to 8.2% (P<0.001). 

Researchers found that the incidence of fatigue, hypertension, hand-foot syndrome, and thrombocytopenia were less common with the 2/1 schedule.

In regard to efficacy, median progression-free survival was 30.2 months in the group that switched schedules, 10.4 months in the 2/1 group, and 9.7 months in the 4/2 group.

Reference

1. Bracarda S, Iacovelli R, Boni L, et al. Sunitinib administered on 2/1 schedule in patients with metastatic renal cell carcinoma: the RAINBOW analysis. Ann Oncol. 2015. [epub ahead of print]. doi: 10.1093/annonc/mdv315.

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Prostate biopsies may result in a decline in erectile function, according to researchers.

In a prospective study, most men who underwent a transrectal ultrasonography (TRUS)-guided prostate biopsy experienced a significant decrease in International Index of Erectile Function-5 (IIEF-5) score, independent of age, cancer diagnosis, and prior biopsy status.

Writing in a paper published in BJU International (2015;116:190-195), investigators concluded that men who undergo TRUS-guided prostate biopsy should be counseled on all of the potential side effects and complications of the procedure.

The study, led by Katie S. Murray, MD, of the University of Kansas Medical Center in Kansas City, enrolled 220 men with a mean age of 64.1 years and a PSA level of 6.7 ng/dL. At presentation, 38.6% reported no erectile dysfunction (ED), 22.3% mild ED, 15.5% mild-to-moderate ED, 10% moderate ED, and 13.6% severe ED. Patients were sent IIEF-5 follow-up questionnaires at 1, 4, and 12 weeks. The number of patients who returned follow-up questionnaires at each follow-up time-point differed (163, 126, and 103 at 1, 4, and 12 weeks, respectively). This led to different baseline mean IIEF-5 scores at each time-point.

At 1 week post-biopsy, the mean IIEF-5 score was significantly lower than it was at baseline (15.5 vs. 18.2). The mean score remained significantly lower compared with baseline at 4 and 12 weeks (17.3 vs. 18.4 and 16.9 vs. 18.4, respectively).

“ED, acute or sub-acute, should be discussed with the patients before biopsy because biopsy has been shown to affect erections in men at many time-points after biopsy,” the authors wrote.

Study results also show that men aged 60 years and older are predisposed to worse erectile function after biopsy, so prostate biopsy should be used even more cautiously in this group, and physician-to-patient counseling “should include this potential outcome in more detail.”

The study also found that patients who had a final prostate cancerdiagnosis were more likely to have a decline in IIEF-5 after biopsy. The precise mechanism of this decline in these patients is most likely multifactorial, the investigators stated. Psychogenic causes, fear of results, anxiety related to biopsy, and even anatomical considerations such as nerve damage and hematoma could potentially have a role, they noted.

In an accompanying editorial (pp. 164-169), Brian T. Helfand, MD, of the North Shore University Health System in Chicago and the University of Chicago, noted that the study by Dr. Murray and her colleagues supports the findings of some retrospective studies but contradicts the findings of others. In a previous study, Dr. Helfand and colleagues demonstrated that a PCa diagnosis is associated with an increased risk of ED after a prostate biopsy, similar to what Dr. Murray and colleagues found.

When the findings of Dr. Murray's team are considered in the context of previous studies on this topic, Dr. Helfand noted, it appears that patients should be counseled on the possibility of short-term changes in erectile function after a prostate biopsy. It also should be emphasized, however, that long-term ED might not be related to the biopsy procedure itself but rather to other factors, included advanced age, psychological stress, and/or PCa diagnosis, according to Dr. Helfand.

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