Toshitaka Morishima

Trends in radiotherapy use and implementation challenges among patients with cervical cancer: a multicenter study in Osaka, Japan

ABSTRACT Since 2018, the staging system and guidelines for cervical cancer have been revised in Japan. Here, we analyzed trends in radiotherapy use among patients with cervical cancer in Osaka Prefecture, Japan. We obtained records from hospital-based cancer registries (2016–23) linked to Diagnosis Procedure Combination data (2019–23), from 67 nationally or prefecturally designated cancer care hospitals. Eligible patients had epithelial or neuroendocrine cervical cancer, excluding those with clinical stage 0 or unknown clinical stage with pathological stage 0. Between 2016 and 2023, the number of patients per year remained stable (717–787); the number of stage IB–IIA (FIGO 2018) cases decreased, whereas that of stages IIB or IIIC (T1–2) cases increased. The number of patients receiving radiotherapy as initial treatment increased from 229 in 2016 to 294 in 2023; this was accompanied by a decline in surgical treatment. The proportion of patients undergoing radiotherapy increased from 11.9% to 17.2% for stage IB–IIA, from 55.6% to 71.7% for stage IIB and from 38.0% to 69.5% for stage IIIC (T1–2). Among 11 institutions providing brachytherapy, the number of radiotherapy cases increased at three, whereas it remained stable or declined at the other eight. These findings indicate a growing trend in radiotherapy use for cervical cancer in Osaka Prefecture; however, the increase varied by institution. To sustain cervical cancer radiotherapy services, further studies may be needed to assess the adequacy of brachytherapy staffing, explore the financial feasibility of brachytherapy equipment, and examine the potential implications of brachytherapy centralization.

Secondary Lower‐Body Sarcomas in Cervical Cancer Survivors Following Surgery, Radiotherapy, or Both: A Population‐Based Study

ABSTRACT Secondary sarcomas in cervical cancer survivors are understudied. We investigated the incidence and subtypes of secondary sarcomas by treatment modalities, the prognosis of secondary sarcomas, and whether surgery plus radiotherapy increases angiosarcoma incidence. This population‐based retrospective cohort study analyzed Osaka Cancer Registry data on women aged 20–84 years diagnosed with cervical cancer (1980–2015), treated with surgery, radiotherapy, or both. Patients with distant metastases, survival time < 1 year, or missing data were excluded. We included 7591 patients with invasive cancer treated with surgery, 3882 with radiotherapy, and 4090 with surgery plus radiotherapy and 13,205 with carcinoma in situ treated with surgery. We assessed the first lower‐body sarcoma occurrence ≥ 1 year post‐diagnosis. Sarcomas developed in 6 patients treated with surgery (0 angiosarcomas), 10 with radiotherapy (1 angiosarcoma), and 19 with surgery plus radiotherapy (9 angiosarcomas). At 10 years, the cumulative incidence was 0.083% (95% confidence interval [CI], 0.024%–0.24%) for radiotherapy and 0.21% (95% CI, 0.10%–0.41%) for surgery plus radiotherapy, higher than that for surgery (invasive, 0.013%; in situ, 0.028%) ( p  < 0.001). Angiosarcoma incidence was higher with surgery plus radiotherapy (0.080%; 95% CI, 0.023%–0.23%) than with radiotherapy (0.028%; 95% CI, 0.003%–0.16%) ( p  = 0.029). Among patients diagnosed with sarcoma after radiotherapy or surgery plus radiotherapy, the 1‐year overall survival rate was 33.3% (95% CI, 19.6%–56.8%). Radiotherapy, alone or combined with surgery, increased secondary lower‐body sarcoma incidence compared with surgery. To our knowledge, this is the first population‐based study to suggest that surgery plus radiotherapy is associated with angiosarcoma in cervical cancer survivors.

Trends in clinical stage distribution and screening detection of cancer in Osaka, Japan: Stomach, colorectum, lung, breast and cervix

We examined clinical stage distribution and proportion of screen-detected cases of stomach, colorectal, lung, female breast and cervical cancer by sex and age group using Osaka Cancer Registry data from 2000–2014. The proportion of local or in situ stage cancer had increased for all age groups in all sites, except stomach cancer in the 0–49 years group and female breast cancer in the 80 years and older group. The proportion of screen-detected cases had increased during the study period for all age groups in all cancer sites. While the proportion increased noticeably in the younger groups, there was only a slight increase in the older groups. Regarding stomach, colorectal and lung cancers, the proportion of local and in situ stage had similarly increased in the 65–79 years and 80 years and older age groups compared with younger groups, despite lower exposure to cancer screening. Regarding breast and cervical cancers, the increases in local and in situ cancer paralleled the increase in screen-detected cases. These findings suggest that the increases in early stage stomach, colorectal and lung cancers might be due not only to the expansion of screening programs but also the development of clinical diagnostic imaging or other reasons. The increases in local and in situ stage breast and cervical cancers seemed to be due to the expansion of screening. Continued monitoring of trends in cancer incidence by clinical stage may be helpful for estimating the effectiveness of screening.

Population-Based Survival Analysis of Stage IVB Small-Cell Neuroendocrine Carcinoma in Comparison to Major Histological Subtypes of Cervical Cancer

The aim of the current study is to investigate the survival outcome of stage IVB SCNEC of the uterine cervix in comparison to major histological subtypes of cervical cancer. A population-based retrospective cohort study was conducted using the Osaka Cancer Registry data from 1994 to 2018. All FIGO 2009 stage IVB cervical cancer patients who displayed squamous cell carcinoma (SCC), adenocarcinoma (A), adenosquamous cell carcinoma (AS), or small-cell neuroendocrine carcinoma (SCNEC) were first identified. The patients were classified into groups according to the types of primary treatment. Then, their survival rates were examined using the Kaplan–Meier method. Overall, in a total of 1158 patients, clearly differential survival rates were observed according to the histological subtypes, and SCNEC was associated with shortest survival. When examined according to the types of primary treatments, SCNEC was associated with significantly decreased survival when compared to SCC or A/AS, except for those treated with surgery. In patients with FIGO 2009 stage IVB cervical cancer, SCNEC was associated with decreased survival when compared to SCC or A/AS. Although current treatments with either surgery, chemotherapy or radiotherapy have some therapeutic efficacies, to improve the prognosis, novel effective treatments specifically targeting cervical SCNEC need to be developed.

Subsequent primary cancer incidence in cervical cancer survivors: insights from a comprehensive cohort study utilizing combined Japanese population-based cancer registries

This study aimed to evaluate the incidence of subsequent primary cancer (SPC) among cervical cancer survivors in Japan. Data from the cancer registries of Osaka, Kanagawa, and Miyagi prefectures were combined. The cohort included individuals diagnosed with invasive and in situ cervical cancer between 1980 and 2010, with the SPC incidence evaluated until 2015. The incidence and standardized incidence ratio (SIR) for different SPC sites were calculated. In addition, the association between SPC and radiotherapy was examined via competitive regression analysis. A total of 49,824 cervical cancer survivors were followed for up to 35 years, during which 4,507 (9.0%) of these survivors experienced SPC. Aside from the initial cancer, SPC was the most common cause of death among cervical cancer survivors. The most frequent SPC sites were the colorectal, breast, lung, and stomach, consistent with the frequency in the general population. A significant increase in the SIRs for bladder, lung, and colorectal cancers was observed (2.52, 1.63, and 1.44, respectively). Individuals who underwent radiotherapy had a higher risk of developing bladder cancer than those who did not, with a subdistribution hazard ratio of 2.28. The SIR for lung cancer significantly increased, particularly for the smoking-associated types, indicating the influence of smoking habits among survivors. Increased risk of specific SPCs was seen in both invasive and in situ cancer survivors. Cervical cancer survivors should be informed about the risks of SPCs and educated on the prevention methods. Our study provides valuable insights into specific actions SPC prevention.