Adjuvant chemo an alternative to radiotherapy in intermediate-risk stage IB cervical cancer
Adjuvant chemotherapy offers comparable survival benefit to radiotherapy-based treatment in patients with intermediate-risk stage IB cervical cancer, results of a Japanese study have shown.
The retrospective analysis included 555 patients with stage IB cervical cancer who had intermediate risk (deep stromal invasion [>50 percent], large tumour size [>4 cm], or lympho-vascular space invasion [LVSI]). Results showed comparable rates of disease-free survival and cause-specific survival at 5 years between patients who received chemotherapy and those who received concurrent chemoradiotherapy (CCRT) as adjuvant treatment. [Oncotarget 2017;8:106866-106875]
After a median follow-up of 5.5 years, disease-free survival rate was 88.1 percent in the chemotherapy group vs 90.2 percent in the CCRT group (adjusted hazard ratio [HR], 0.98; p=0.94), while cause-specific survival rate was 95.4 percent vs 94.8 percent (adjusted HR, 0.85; p=0.71).
Results were similar in a subgroup of 329 patients with multiple intermediate-risk factors. In these patients, the 5-year rate of disease-free survival was 87.1 percent for those who received chemotherapy vs 90.2 percent for those who received CCRT (p=0.86), while the 5-year rate of cause-specific survival was 94.6 percent vs 93.4 percent (p=0.82).
The risks of local recurrence (p=0.77) and distant recurrence (p=0.94) were likewise not affected by the type of adjuvant therapy given.
Interestingly, patients whose tumours exhibited LVSI as the only intermediate-risk factor had similar survival outcomes compared with those who had multiple risk factors. At 5 years, the rate of disease-free survival was 87.9 vs 85.9–90.2 percent.
The researchers also found a minimal risk of recurrence in patients with large tumour size or deep cervical stromal invasion without other risk factors. The rate of 5-year disease-free survival in these patients was 94.8 percent and 100 percent, respectively.
“The current intermediate-risk criteria as per the Japanese Society of Gynecologic Oncology need to be revised, as they may result in overtreatment of patients whose prognosis is generally favourable,” the researchers suggested.
Based on the results of the current study, the presence of at least two risk factors or LVSI alone may meet the criteria for stratification into the intermediate-risk category, they added.
Patients in the retrospective analysis were previously enrolled in a nation-wide cohort study (n=6,003) in Japan. Among the 555 patients included in the analysis, the most common intermediate-risk factor was LVSI (76.9 percent), followed by deep stromal invasion (70.6 percent).
In the chemotherapy group, the most commonly chosen regimen was a taxane/platinum doublet (52.2 percent), followed by irinotecan-based regimens (19.7 percent). A median of four chemotherapy cycles were administered.
“Chemotherapy may be an alternative and effective option for the adjuvant treatment of patients with intermediate-risk stage IB cervical cancer,” the researchers concluded. “This option can be particularly suitable for patients who are not the best candidates for radiotherapy. Moreover, a reduction in the number of chemotherapy cycles may be considered because an increased number of chemotherapy cycles did not improve survival, and patients in the intermediate-risk group generally had a good prognosis.”