In JAMA this week, a team of US researchers reports on predicting long-term erectile function in prostate cancer patients after treatment. The team noted pretreatment patient characteristics, sexual health-related quality-of-life assessments, and treatment details for a cohort of patients and developed models to predict erectile function two years after treatment. The team then validated those models with data from a different cohort of patients. Two years after undergoing treatment for prostate cancer, 37 percent of the patients in the study cohort and 48 percent of those with functional erections prior to treatment reported functional erections. "Pretreatment sexual health-related quality of life score, age, serum prostate-specific antigen level, race/ethnicity, body mass index, and intended treatment details were associated with functional erections two years after treatment," the researchers write. "Stratification by pretreatment patient characteristics and treatment details enables prediction of erectile function two years after prostatectomy, external radiotherapy, or brachytherapy for prostate cancer."
Also in JAMA this week, researchers respond to a meta-analysis review published in JAMA earlier this year on the associations between time to initiation of adjuvant chemotherapy for colorectal cancer patients and survival. The review by Biagi et al. concluded that longer time to initiation of treatment after tumor resection was associated with a worse survival outcome for colorectal cancer patients. In a letter to the editor in this week's JAMA, researchers from the Mayo Clinic and the University of Birmingham say that Biagi et al.'s conclusions weren't justified by the data: Patients that started treatment later had worse survival outcomes could be explained by those patients having significant comorbidities and recovering from surgery less quickly, and therefore starting chemotherapy later, the letter's authors write. "The data fail the criteria for strength (an estimated hazard ratio of 1.14); consistency (the analysis was dominated by 1 large observational study); and, most importantly, specificity (alternative hypotheses exist that are consistent with the data). Only randomized trials can provide meaningful evidence on the effect of delaying chemotherapy," they add. "Although starting chemotherapy as soon as practical seems advisable, starting therapy too early may have a negative rather than a positive effect." In response, Biagi et al. disagree that their data was not meaningful, and say that their review took comorbidity into account when reaching their conclusions. "We disagree that randomized trials are the only way to establish a relationship between wait time and survival. It is unlikely such a trial would ever gain support," they write, adding, "While it is inappropriate to use adjuvant chemotherapy if a patient has not recovered from surgery, the predominant factors leading to treatment delay in routine practice relate to logistics in the cancer system, and these should be minimized as much as possible."