Carcinoma In Situ Skip Lesions of the Uterine Corpus in Cervical Squamous Cell Carcinoma: Impact on Target Setting in Radiotherapy
Mayumi Harada, Yasuhito Hagiwara, Takanobu Kabasawa, Hiraku Sato, Mayumi Ichikawa, Hiroko Akamatsu, Takashi Kaneko, Natsuko Yano, Ken Uematsu, Masanori Komatsu, Taiyo Tanae, Kenji Nemoto, Masashi KotoABSTRACT
Background
In definitive radiotherapy for FIGO Stage I–III cervical cancer, external beam radiotherapy and/or brachytherapy are used—alone or in combination with concurrent chemotherapy depending on stage—with target delineation largely guided by clinically apparent disease. However, discontinuous carcinoma in situ (CIS) “skip lesions” within the uterine corpus are well described in cervical adenocarcinoma, whereas their presence in cervical squamous cell carcinoma (SCC) has not been systematically evaluated.
Aims
This study aimed to investigate the presence or absence of CIS skip lesions in the uterine corpus of patients with cervical SCC.
Methods and Results
This retrospective study included all patients who underwent total or radical hysterectomy for cervical SCC at Yamagata University Hospital between January 2013 and April 2020. Patients who underwent prior radiotherapy or preoperative chemotherapy, or had non‐squamous histological components, were excluded. Fifty patients were enrolled. Pathological examination of serially sectioned uterine specimens was conducted to identify skip lesions, defined as discontinuous CIS lesions in the uterine corpus, as confirmed by a pathologist and a radiation oncologist. Pathological evaluation showed that 29 patients (58%) had FIGO Stage I disease, 6 patients (12%) had FIGO Stage II disease, and 15 patients (30%) were classified as FIGO Stage IIIC1. Preoperative imaging studies did not identify any skip lesions in the uterine corpus. However, one patient (2%; Clopper–Pearson 95% confidence intervals: 0.05%–10.5%) presented with a histologically confirmed CIS skip lesion located in the uterine corpus, approximately 2 cm cranial to the primary tumor margin, that was undetectable on imaging. The primary tumor after biopsy measured 3 mm and was diagnosed as non‐keratinizing SCC without > 1/3 stromal invasion. Lymphovascular space invasion, parametrial invasion, and corpus invasion were not observed.
Conclusion
Although rare, CIS skip lesions in the uterine corpus can occur in patients with cervical SCC.