Second primary uterine malignancies after radiation therapy for cervical cancer

PURPOSE

Radiation exposure has long been established as a risk factor for cancer development. The purpose of this study is to assess the risk of uterine malignancy in patients previously treated for cervical cancer with radiation therapy.

METHODS

A population-based cohort of 9092 patients diagnosed with cervical cancer who did not undergo surgery and received radiation therapy between 1973 and 2008 was identified from the Surveillance, Epidemiology and End Results Program database (SEER 9). Patients in this cohort who developed endometrial cancer after treatment of cervical cancer were identified. 55,140 patients with endometrial cancer were also identified. The distribution of the different histologic types of endometrial cancer was determined for each of these cohorts.

RESULTS

54 patients (0.6%) were diagnosed with an endometrial cancer more than 12 months after diagnosis of cervical cancer. The average latency to endometrial cancer diagnosis was 160 months, with a range of 14-374 months. The average age of cervical cancer diagnosis was 52 years and the average age at subsequent endometrial cancer diagnosis was 66 years. Only 40% of the endometrial cancers diagnosed following treatment of cervical cancer were endometrioid. The majority were clear-cell adenocarcinomas (42%), 9% were carcinosarcomas and 5.5% were leiomyosarcomas. Of the 55,140 endometrial cancer patients in the database, a vast majority were endometrioid adenocarcinomas (91%), and only 2.3% clear-cell adenocarcinoma, 2.3% carcinosarcoma and 0.5% leiomyosarcoma. The difference in histologic type distribution between these two cohorts is highly significant (p < 0.01).

CONCLUSION

A small proportion of women who receive radiation for cervical cancer go on to develop endometrial cancer. These are predominantly of the more aggressive histologic types when compared to primary endometrial cancers. The latency from cervical cancer diagnosis to endometrial cancer diagnosis is over a decade. In a patient who still has a uterus after receiving pelvic radiation, vaginal bleeding should be investigated.

Radiation-Induced Malignancies: Our Experiences With Five Cases

Radiotherapy is one of the modalities of treatment of malignancies. Radiation-induced malignancies (RIMs) are late complications of radiotherapy, seen among the survivors of both adult and pediatric cancers. Mutagenesis of normal tissues is the likely basis for RIMs. Till date, RIM cannot be differentiated from primary cancers. We present a series of five patients who were treated at our institute between 2002 and 2016 and were subsequently diagnosed with RIM. Out of five patients, there were two cases of sarcomas, two of carcinomas and one neuroendocrine carcinoma of tongue (rare entity). Separate treatment guidelines are not available for RIM, so the treatment given was same as primary malignancies.

Radiation-Induced Malignancies Making Radiotherapy a "Two-Edged Sword": A Review of Literature

Radiotherapy is one of the modalities of treatment of malignancies. Radiation-induced malignancies (RIMs) are late complications of radiotherapy, seen among the survivors of both adult and pediatric cancers. Mutagenesis of normal tissues is the basis for RIMs. The aim of this review of literature was to discuss epidemiology, factors affecting and different settings in which RIM occur.