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Risk of Secondary Malignancy After Radiotherapy for Breast Cancer: Long-term Follow-up of Japanese Patients with Breast Cancer

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Specialty Oncology
Date 2022 Jul 5
PMID 35781767
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Abstract

Purpose: There have been very few reports of secondary malignancies after breast cancer treatment in Asia, particularly in Japan. This study aimed to evaluate the risk of secondary malignancies after radiotherapy (RT) in Japanese breast cancer patients.

Methods: This single-center retrospective study included patients who underwent RT between July 1961 and September 2006 for postoperative breast cancer. A total of 702 patients with a follow-up period of more than 5 years were analyzed. All malignancies observed at more than 5 years after the start of RT were defined as secondary malignancies. To calculate the relative risk (RR) of secondary malignancies, we applied data from the National Cancer Center in Japan.

Results: The median observation period was 9.7 (interquartile range 7.1-18.2) years. The cumulative person-years of observation were 6879.4. The RR of contralateral breast cancer increased by 1.85-fold (95% confidence interval [CI] 1.05-3.26) among patients compared with that among the general population; however, the difference was not significant (p = 0.053). The RR of secondary malignancies other than breast cancer increased by 2.71-fold (95% CI 1.99-3.70, p < 0.001) among the patients compared with the general population. Even when only malignancies detected more than 10 years after RT were defined as secondary malignancies, the RR of secondary malignancies other than breast cancer was 1.91 (95% CI 1.33-2.73, p < 0.001).

Conclusion: The incidence of secondary malignancies after RT may be somewhat higher in Japanese patients with breast cancer than in the general population.

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References
1.
Shaitelman S, Chiang Y, Griffin K, DeSnyder S, Smith B, Schaverien M . Radiation therapy targets and the risk of breast cancer-related lymphedema: a systematic review and network meta-analysis. Breast Cancer Res Treat. 2016; 162(2):201-215. DOI: 10.1007/s10549-016-4089-0. View

2.
Ademuyiwa F, Olopade O . Racial differences in genetic factors associated with breast cancer. Cancer Metastasis Rev. 2003; 22(1):47-53. DOI: 10.1023/a:1022259901319. View

3.
Calip G, Law E, Ko N . Racial and ethnic differences in risk of second primary cancers among breast cancer survivors. Breast Cancer Res Treat. 2015; 151(3):687-96. PMC: 4501770. DOI: 10.1007/s10549-015-3439-7. View

4.
Terao C, Suzuki A, Momozawa Y, Akiyama M, Ishigaki K, Yamamoto K . Chromosomal alterations among age-related haematopoietic clones in Japan. Nature. 2020; 584(7819):130-135. PMC: 7489641. DOI: 10.1038/s41586-020-2426-2. View

5.
Taylor C, Correa C, Duane F, Aznar M, Anderson S, Bergh J . Estimating the Risks of Breast Cancer Radiotherapy: Evidence From Modern Radiation Doses to the Lungs and Heart and From Previous Randomized Trials. J Clin Oncol. 2017; 35(15):1641-1649. PMC: 5548226. DOI: 10.1200/JCO.2016.72.0722. View