Effect of radiotherapy on the survival of cervical cancer patients: An analysis based on SEER database

Abstract

Cervical cancer is among the most frequent cancer types in women worldwide. Radiotherapy, including external beam radiation and brachytherapy, is one of the commonly used treatment options for cervical cancer. However, the adverse effects of radiation therapy on cervical cancer survival have been poorly investigated with inconclusive results. Therefore, the aim of this study was to determine the suitable radiotherapy modality according to patients' characteristics. A retrospective survival analysis of 44,602 patients was performed using the Surveillance, Epidemiology, and End Results (SEER) database. Multivariate proportional hazard Cox model was used to evaluate the prognostic impact of different radiotherapy modalities, primary surgery, age, TNM stage, and tumor size. Our results indicated that patients without primary surgery, diagnosed at older age (≥45 years' old), at advanced TNM stages (III/IV) or with larger tumor size (≥3 cm) could benefit from radiotherapy. However, radiotherapy was detrimental in patients with primary surgery, diagnosed at younger age (<45 years' old), at earlier TNM stages (I/II) or with smaller tumor size (<3 cm). In addition, external beam radiation was in most cases less effective compared with combined external beam and brachytherapy. These results highlighted the necessity of realizing personalized radiotherapy treatments for patients with cervical cancer.

Figure 1

Survival curves in cervical cancer patients according to radiotherapy stratified by primary surgery. (A) Overall survival of no primary surgery group, χ² = 1577.663, P < .001. (B) Cause-specific survival of no primary surgery group, χ² = 1364.916, P < .001. (C) Overall survival of primary surgery group, χ² = 2184.722, P < .001. (D) Cause-specific survival of primary surgery group, χ² = 2234.601, P < .001.

Figure 2

Survival curves in cervical cancer patients according to radiotherapy stratified by TNM stage. (A) Overall survival of stage I/II group, χ² = 2590.879, P < .001. (B) Cause-specific survival of stage I/II group, χ² = 2296.589, P < .001. (C) Overall survival of stage III/IV group, χ² = 1573.882, P < .001. (D) Cause-specific survival of stage III/IV group, χ² = 1431.397, P < .001.

Figure 3

Survival curves in cervical cancer patients according to radiotherapy stratified by age at diagnosis. (A) Overall survival of younger group, χ² = 2867.453, P < .001. (B) Cause-specific survival of younger group, χ² = 2815.305, P < .001. (C) Overall survival of older group, χ² = 920.560, P < .001. (D) Cause-specific survival of older group, χ² = 897.282, P < .001.

Figure 4

Survival curves in cervical cancer patients according to radiotherapy stratified by tumor size. (A) Overall survival of smaller tumor group, χ² = 774.510, P < .001. (B) Cause-specific survival of smaller tumor group, χ² = 717.422, P < .001. (C) Overall survival of large tumor group, χ² = 253.402, P < .001. (D) Cause-specific survival of large tumor group, χ² = 229.275, P < .001.