Populational trends and outcomes of postoperative radiotherapy for high-risk early-stage cervical cancer with lymph node metastasis: concurrent chemo-radiotherapy versus radiotherapy alone.

BACKGROUND: Pelvic lymph node metastasis carries the highest impact on decreased survival among surgical-pathological risk factors for early-stage cervical cancer. While concurrent administration of chemotherapy during postoperative radiotherapy is the current standard treatment for surgically-treated high-risk early-stage cervical cancer, its effectiveness specific to node-positive disease has not been completely studied.

OBJECTIVE: To examine the association between the use of concurrent chemotherapy and survival in women with early-stage cervical cancer and nodal metastasis receiving adjuvant radiotherapy.

METHODS: This is a population-based cohort study using the Surveillance, Epidemiology, and End Results Program from 1988-2016. Women with stage T1-2 cervical cancer with pelvic lymph node metastasis who underwent hysterectomy and received postoperative radiotherapy were examined. Trends, characteristics, and overall survival (OS) were compared between women who received postoperative radiotherapy alone (n=729) or in combination with CCRT (n=1,809). Propensity score-based inverse probability of treatment weighting was used to account for the effect of measured covariates on treatment selection.

RESULTS: Among 2,538 women, there was a marked increase in the use of concurrent chemotherapy from 1997-2000 (20.7% to 78.5%, P=0.052) followed by a more gradual rise through 2016 (88.3%, P<0.001). In a multivariable model, women with non-squamous cell carcinomas and those diagnosed more recently were more likely to receive CCRT, while older women were less likely to receive CCRT (all, P<0.05). At the population level, the 5-year OS rates remained unchanged (annual percent change for 1997-2012 -0.1, 95% confidence interval [CI] -1.2 to 1.0, P=0.776). In a propensity score weighted cohort, women who received CCRT had a 5-year OS rate similar to those treated with radiotherapy alone (73.1% versus 73.6%, hazard ratio 1.004, 95%CI 0.887-1.136, P=0.955). Significant differences were also not seen in older women, non-squamous types, stage T2 disease, and multiple node metastases (all, P>0.05).

CONCLUSION: Despite the marked increase in the use of CCRT for women with early-stage cervical cancer and nodal metastases, there was no association between use of concurrent chemotherapy during postoperative radiotherapy and improved survival.