Clinical utilization of radiation therapy in Korea, 2016

Irradiation-responsive PRDM10-DT modulates the angiogenic response in human NSCLC cells in an SP1-dependent manner via the miR-663a/TGF-β1 axis

BACKGROUND

Photon radiation has been shown to stimulate the secretion of radioresistant factors from tumor cells, ultimately promoting tumor angiogenesis and metastasis. On the other hand, heavy-ion radiotherapy has been demonstrated to control tumor angiogenesis and metastasis levels. The molecular mechanisms responsible for the different angiogenic responses to photon and heavy-ion irradiation are not fully understood. This study aims to explore the irradiation-responsive genes related to tumor angiogenesis and reveal the regulatory effect.

METHODS

In order to clarify the potential regulatory mechanisms of tumor angiogenesis after X-ray or carbon ion (C-ion) irradiation, we performed RNA-sequencing (RNA-seq), as well as bioinformatics, public database analysis, Western blotting, immunohistochemistry, and immunofluorescence.

RESULTS

In this study, we identified the long intergenic noncoding RNA PRDM10 divergent transcript (PRDM10-DT), which was responsive to X-rays but not carbon ions. Mechanistically, PRDM10-DT triggers tumor angiogenesis by upregulating the TGF-β1/VEGF signaling pathway through its competitive binding to miR-663a. Additionally, the transcription factor SP1 facilitated the transcription of PRDM10-DT by binding to its promoter region. It's notable that the DNA-binding activity of SP1 was enhanced by reactive oxygen species (ROS). The knockdown of either PRDM10-DT or SP1 effectively inhibited NSCLC angiogenesis and metastasis.

CONCLUSION

These results illustrate the proangiogenic function of the PRDM10-DT/miR-663a/TGF-β1 axis and reveal the regulatory role of ROS and SP1 in the upstream response to radiation, with differential ROS production mediating the differential angiogenesis levels after X-ray and C-ion irradiation. Our findings suggest the potential of PRDM10-DT as a nucleic acid biomarker after radiotherapy and that targeting this gene could be a therapeutic strategy to counteract angiogenesis in NSCLC radiotherapy.

Operational Definitions of Colorectal Cancer in the Korean National Health Insurance Database

OBJECTIVES

We reviewed the operational definitions of colorectal cancer (CRC) from studies using the Korean National Health Insurance Service (NHIS) and compared CRC incidence derived from the commonly used operational definitions in the literature with the statistics reported by the Korea Central Cancer Registry (KCCR).

METHODS

We searched the MEDLINE and KoreaMed databases to identify studies containing operational definitions of CRC, published until January 15, 2021. All pertinent data concerning the study period, the utilized database, and the outcome variable were extracted. Within the NHIS-National Sample Cohort, age-standardized incidence rates (ASRs) of CRC were calculated for each operational definition found in the literature between 2005 and 2019. These rates were then compared with ASRs from the KCCR.

RESULTS

From the 62 eligible studies, 9 operational definitions for CRC were identified. The most commonly used operational definition was "C18-C20" (n=20), followed by "C18-C20 with claim code for treatment" (n=3) and "C18-C20 with V193 (code for registered cancer patients' payment deduction)" (n=3). The ASRs reported using these operational definitions were lower than the ASRs from KCCR, except for "C18-C20 used as the main diagnosis." The smallest difference in ASRs was observed for "C18-C20," followed by "C18- C20 with V193," and "C18-C20 with claim code for hospitalization or code for treatment."

CONCLUSIONS

In defining CRC patients utilizing the NHIS database, the ASR derived through the operational definition of "C18-C20 as the main diagnosis" was comparable to the ASR from the KCCR. Depending on the study hypothesis, operational definitions using treatment codes may be utilized.

Pattern of practice for postoperative management of endometrial cancer in Korea: a survey by the Korean Gynecologic Oncology Group and the Korean Radiation Oncology Group (KGOG 2028-KROG 2104)

OBJECTIVE

This study aimed to investigate the current status of postoperative management of uterine endometrial cancer (EC) in Korea.

METHODS

A mail survey was administered to members of the Korean Gynecologic Oncology Group and Korean Radiation Oncology Group. A total of 38 gynecologic cancer surgeons (GYNs) and 31 radiation oncologists (RO) in 43 institutions was responded. The questionnaire consisted of general questions for clinical decision and clinical case questions. The GYN and RO responses were compared using chi-square statistics.

RESULTS

The 2 expert groups had similar responses for clinical decision based on the results of the Gynecologic Oncology Group (GOG)-249 and Postoperative Radiation Therapy for Endometrial Carcinoma-III trials in the early-stage EC. In contrast, the responses based on GOG-258 results differed, as GYNs most frequently opted for sequential chemotherapy (CTx) and radiotherapy (RT), while ROs preferred concurrent chemoradiotherapy in locally advanced stage (p<0.05). Based on the GOG-258, GYNs preferred CTx alone for adjuvant treatment of serous or clear cell adenocarcinoma histology, whereas ROs advocated for combined CTx and RT (sequential or concurrent). Among the clinical case questions, GYNs were more likely than ROs to choose CTx alone rather than the combination of CTx and RT (sequential or concurrent) as the answers to case questions representing patients with locally advanced stage or unfavorable histology (all p<0.05).

CONCLUSION

The present study showed several different opinions of GYNs and ROs regarding adjuvant treatment for EC, particularly for adjuvant RT in advanced stage or unfavorable histology.

Clinical utilization of radiation therapy in Korea between 2017 and 2019

PURPOSE

This study aimed to evaluate the clinical infrastructure and utilization of radiotherapy (RT) services in Korea between 2017 and 2019.

MATERIALS AND METHODS

We extracted the data of patients who underwent RT between 2017 and 2019 from the Health Insurance Review and Assessment Service. We further analyzed this data according to the diagnosis and treatment modalities of patients diagnosed with International Classification of Disease 10 (ICD-10) diagnostic codes C00-C97 and D00-D48. In addition, we collected statistics on RT facilities in Korea using a nationwide survey.

RESULTS

The total number of patients who received RT in 2017, 2018, and 2019 were 77,901, 81,849, and 87,460, respectively. The number of patients diagnosed with ICD 10 C- and D-codes in 2019 was 86,339, of whom 39,467 were men and 46,872 women. The rate of utilization of RT among cancer patients was 30.4% in 2017 and 2018 and 30.9% in 2019. In 2019, the most common types of cancers treated with RT were breast, lung, prostate, colorectal, and liver cancers. Regarding the RT infrastructure in Korea, there were 95 radiation oncology centers, 237 megavoltage (MV) teletherapy units, 35 brachytherapy units, and two proton accelerators in 2019. There were 4.5 MV teletherapy machines per million.

CONCLUSION

The number of patients treated with RT has increased consistently from 2017 to 2019. As the number of patients with cancer increases, it is expected that the RT infrastructure will be further expanded in Korea.

Current usage of stereotactic body radiotherapy for oligometastatic prostate cancer in Korea: patterns of care survey (KROG 19-08)

Background

Growing evidence suggests that metastasis-directed therapy and/or prostate-directed therapy may benefit patients with oligometastatic prostate cancer (OMPC). Stereotactic body radiotherapy (SBRT) is increasingly used to treat oligometastases in various cancers. The purpose of this study was to investigate the current patterns of curative-intent SBRT for OMPC in Korea.

Methods

A 20-item questionnaire was sent to 326 radiation oncologists in 93 institutions in Korea. Only 1 physician per institution was required to complete the survey. Subsequently, the second survey consisting of 3 clinical scenarios was sent to 64 physicians with clinical experience in SBRT: case 1, cT4N0M1 (direct invasion to two pelvic bones); case 2, cT2N0M1 (three bone metastases); and case 3, solitary spine metastasis after radical prostatectomy.

Results

Seventy-six physicians from 93 institutions (82%) answered the first survey. The multidisciplinary team approach was practiced in 16 institutions (21%). Most physicians (75%) agreed on the definition of oligometastases as limited lesions and/or organs ≤5: 25% agreed with low-volume disease according to CHAARTED trial. During the last year, 49 physicians (64%) treated OMPC patients with curative intent. Sixty four physicians (84%) had a clinical experience with SBRT: 48 (75%) stated that both dose and fraction number should be considered when defining SBRT, whereas others (25%) stated that only fraction size should be considered. Fifty-five faculties (86%) answered the second survey. Physicians agreed with oligometastases in 89% for case 1, in 80% for case 2, and in 100% for case 3. The rate of SBRT application was the highest in case 3 (70%).

Conclusions

There was diversity in the patterns of SBRT for OMPC in Korea. Additional prospective studies are necessary to strengthen evidence regarding role of SBRT in OMPC.

Patterns of Proton Beam Therapy Use in Clinical Practice Between 2007 and 2019 in Korea

Purpose

Proton beam therapy (PBT) is a state-of-the-art technology employed in radiotherapy (RT) for cancer patients. This study characterized how PBT has been used in clinical practice in Korea.

Materials and Methods

Patients who received any type of RT between 2007 and 2019 were identified from the radiation oncology registry of the two PBT facilities operating in Korea (National Cancer Center and Samsung Medical Center). The χ2 test was used to identify patient- and treatment-related characteristics associated with the receipt of PBT.

Results

A total of 54,035 patients had been treated with some form of RT in the two institutions, of whom 5,398 received PBT (10.0%). The number of patients who receive PBT has gradually increased since PBT first started, from 162 patients in 2007 to 1304 patients in 2019. Among all types of cancer, PBT use in liver cancer has been steadily increasing from 20% in 2008-2009 to 32% in 2018-2019. In contrast, that in prostate cancer has been continuously decreasing from 20% in 2008-2009 to <10% in 2018-2019. Male sex, very young or old age, stage I-II disease, residency in non-capital areas, a definitive setting, a curative treatment aim, enrollment in a clinical trial, re-irradiation and insurance coverage were significantly associated with the receipt of PBT (all p < 0.05).

Conclusion

Since PBT started in Korea, the number of patients receiving PBT has increased to more than 1,000 per year and treatment indications have expanded. Liver cancer is the most common primary tumor among all PBT cases in Korea.

Implications of Radiotherapy Utilization in Korea from 2010 to 2019

BACKGROUND

This study was to assess the rate of radiotherapy (RT) utilization according to the modality in South Korea to identify the implications of contemporary RT patterns.

METHODS

We collected information from claims and reimbursement records of the National Health Insurance Service from 2010 to 2019. We classified the location of each institution as capital (Seoul, Incheon, and Gyeonggi-do) and non-capital areas.

RESULTS

The rate of RT utilization in total cancer patients nationwide was 24.5% in 2010, which consistently has increased to 36.1% in 2019 (annual increase estimate [AIE], 4.5%). There was an abrupt increase in patients receiving intensity-modulated RT (IMRT), with an AIE of 33.5%, and a steady decline in patients receiving three-dimensional conformal RT (3DCRT), with an AIE of -7.1%. The commonest RT modality was IMRT (44.5%), followed by 3DCRT and stereotactic RT (SRT) (37.2% and 13.5%) in 2019. An increasing trend of advanced RT (such as IMRT and SRT) utilization was observed regardless of the region, although the AIE in the capital areas was slightly higher than that in non-capital areas.

CONCLUSION

The utilization of overall RT application and especially of advanced modalities remarkably increased from 2010 to 2019. We also found gaps in their AIEs between capital and non-capital areas. We should ensure that advanced RT is accessible to all cancer patients across South Korea.