Nomograms Predicting Progression-Free Survival, Overall Survival, and Pelvic Recurrence in Locally Advanced Cervical Cancer Developed From an Analysis of Identifiable Prognostic Factors in Patients From NRG Oncology/Gynecologic Oncology Group Randomized Trials of Chemoradiotherapy

Abstract

Purpose: To evaluate the prognostic factors in locally advanced cervical cancer limited to the pelvis and develop nomograms for 2-year progression-free survival (PFS), 5-year overall survival (OS), and pelvic recurrence.

Patients and methods: We retrospectively reviewed 2,042 patients with locally advanced cervical carcinoma enrolled onto Gynecologic Oncology Group clinical trials of concurrent cisplatin-based chemotherapy and radiotherapy. Nomograms for 2-year PFS, five-year OS, and pelvic recurrence were created as visualizations of Cox proportional hazards regression models. The models were validated by bootstrap-corrected, relatively unbiased estimates of discrimination and calibration.

Results: Multivariable analysis identified prognostic factors including histology, race/ethnicity, performance status, tumor size, International Federation of Gynecology and Obstetrics stage, tumor grade, pelvic node status, and treatment with concurrent cisplatin-based chemotherapy. PFS, OS, and pelvic recurrence nomograms had bootstrap-corrected concordance indices of 0.62, 0.64, and 0.73, respectively, and were well calibrated.

Conclusion: Prognostic factors were used to develop nomograms for 2-year PFS, 5-year OS, and pelvic recurrence for locally advanced cervical cancer clinically limited to the pelvis treated with concurrent cisplatin-based chemotherapy and radiotherapy. These nomograms can be used to better estimate individual and collective outcomes.

Fig 1.

Nomogram for predicting 2-year progression-free survival (PFS). To use, find patient's histology on histology axis, then draw straight line upward to points axis to determine how many points toward progression patient receives for histology. Do this again for other axes, each time drawing straight line upward toward points axis. Sum points received for each predictor, and find sum on total points axis. Draw straight line down to survival-probability axis to find patient's probability of no progression of cervical cancer at 2 years. For cohort of women exactly like patient, we would expect between (predicted probability [PP] − 0.10) × 100% and (PP + 0.10) × 100% of them to remain free of disease after 2 years. For example, patient receives following number of points for each specific characteristic: histology, adenocarcinoma/adenosquamous carcinoma (17 points); race, white (18 points); performance status, 2 to 3 (35 points); tumor size, 6 cm (60 points); International Federation of Gynecology and Obstetrics (FIGO) stage, IIA (23 points); grade, poor (25 points); pelvic nodes, negative (0 points); and treatment: radiotherapy (RT) plus cisplatin (CDDP; 0 points). Points total is 17 + 18 + 35 + 60 + 23 + 25 + 0 + 0 = 178, and straight line drawn down from total points axis at 178 crosses PP axis at approximately 0.55. Therefore, patient's PP of 2-year PFS is within 0.55 ± 0.10 = 0.55 (95% confidence limits, 0.45 to 0.65).

Fig 2.

Calibration curve for progression-free survival nomogram model. Dashed line represents ideal nomogram, and solid line represents observed nomogram. Vertical bars indicate 95% CIs, and crosses indicate bias-corrected estimates.

Fig 3.

Nomogram for predicting 5-year overall survival (OS). To use, find patient's histology on histology axis, then draw straight line upward to points axis to determine how many points toward death patient receives for histology. Do this again for other axes, each time drawing straight line upward toward points axis. Sum points received for each predictor, and find sum on total points axis. Draw straight line down to survival-probability axis to find patient's probability of surviving cervical cancer for 5 years. For cohort of women exactly like patient, we would expect between (predicted probability [PP] − 0.10) × 100% and (PP + 0.10) × 100% of them to survive for 5 years. CDDP, cisplatin; FIGO, International Federation of Gynecology and Obstetrics; PA, para-aortic; RT, radiotherapy.

Fig 4.

Calibration curve for overall survival nomogram model. Dashed line represents ideal nomogram, and solid line represents observed nomogram. Vertical bars indicate 95% CIs, and crosses indicate bias-corrected estimates.

Fig 5.

Nomogram for predicting pelvic recurrence. To use, find patient's cell type on histology axis, then draw straight line upward to points axis to determine how many points toward pelvic recurrence patient receives for cell type. Do this again for other axes, each time drawing straight line upward toward points axis. Sum points received for each predictor, and find sum on total points axis. Draw straight line down to recurrence-probability axis to find patient's probability of pelvic recurrence. CDDP, cisplatin; FIGO, International Federation of Gynecology and Obstetrics; RT, radiotherapy.