To the Editor Petrelli and colleagues1 assessed the noninferiority of 3-month vs 6-month adjuvant chemotherapy for relapse-free survival (RFS). The hazard ratio (shorter vs longer) was 1.41. Because the CI upper bound of 1.89 exceeded the prespecified noninferiority margin of 1.2, there was insufficient evidence to claim that short-term therapy was noninferior to long-term therapy. However, the greater than 41% increase in hazard is difficult to interpret. Using reconstructed RFS data, with 8 years of follow-up, the mean RFS times were 6.86 and 7.19 years for shorter and longer therapies. The difference of 4.0 months (95% CI, 0.9-7.0; P = .01) was only 4% of the 96 months of follow-up. On the other hand, the rates of severe toxic effects were substantially higher in the 6-month arm. For example, 8.4% of patients in the 6-month arm experienced grade 3 to 4 neuropathy compared with only 1.3% of patients in the 3-month arm. Similar trends were observed for the other adverse events. It is challenging to make an overall risk-benefit assessment based on these separate summaries, one for efficacy and the other for toxicity. Moreover, it is unclear whether the efficacy and toxicity outcomes occurred together in the same patients. This difficulty is reflected in the authors’ vague conclusions that either short-term or long-term therapy can be used for stage II colorectal cancer.1
Identify all potential conflicts of interest that might be relevant to your comment.
Conflicts of interest comprise financial interests, activities, and relationships within the past 3 years including but not limited to employment, affiliation, grants or funding, consultancies, honoraria or payment, speaker's bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued.
Err on the side of full disclosure.
If you have no conflicts of interest, check "No potential conflicts of interest" in the box below. The information will be posted with your response.
Not all submitted comments are published. Please see our commenting policy for details.
McCaw ZR, Kim DH, Wei L. Risk-Benefit Comparisons Between Shorter and Longer Durations of Adjuvant Chemotherapy in High-Risk Stage II Colorectal Cancer. JAMA Oncol. 2020;6(8):1301–1302. doi:10.1001/jamaoncol.2020.2256
Coronavirus Resource Center
Customize your JAMA Network experience by selecting one or more topics from the list below.
Create a personal account or sign in to: