# Second cancers after radiotherapy

Source: https://onco.cc/terms/second-cancers-after-radiotherapy/  
OnCo record `second-cancers-after-radiotherapy` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Radiotherapy can itself cause a new cancer in the treated area, typically ten to thirty years later. The risk is small for most adults but matters greatly for children and young adults.

## Summary

Radiation-induced second cancers include sarcomas in the treated field, breast cancer after chest radiotherapy in young women (as in Hodgkin lymphoma survivors), thyroid and brain tumours after childhood treatment, and leukaemias. The risk rises with dose, volume, young age and genetic predisposition, and is one of the strongest arguments for proton therapy in children, for avoiding radiotherapy where equivalent alternatives exist, and for the lifelong surveillance built into survivorship care.

## Fields

- Kind: Term
- Last checked: 2026-09-17
- Tags: radiation-wave1

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Radiation-induced_cancer
- Wikipedia: https://en.wikipedia.org/wiki/Radiation-induced_cancer

## Connected records

- terms: [Age, smoking and inherited predisposition: what the treatment risk is added to](https://onco.cc/terms/rejuv-second-age-smoking-and-inherited-risk/), [Bowel cancer after abdominal and pelvic radiotherapy](https://onco.cc/terms/second-primary-bowel-after-abdominal-radiotherapy/), [Breast cancer after chest radiotherapy given young](https://onco.cc/terms/second-primary-breast-after-chest-radiotherapy/), [Choices made at the time of treatment that change the second cancer risk](https://onco.cc/terms/rejuv-second-choices-made-at-treatment/), [Lung cancer after chest radiotherapy and after alkylating chemotherapy](https://onco.cc/terms/second-primary-lung-after-chest-radiotherapy/), [Radiotherapy and second cancers: field, dose and age at exposure](https://onco.cc/terms/rejuv-second-radiotherapy-dose-field-and-age/), [Sarcoma in the radiotherapy field, and angiosarcoma of the treated breast](https://onco.cc/terms/second-primary-sarcoma-in-the-treated-field/), [Second cancers after treatment: what the risk is, and what is done about it](https://onco.cc/terms/rejuv-second-cancers-overview/), [Skin cancer after cancer treatment](https://onco.cc/terms/second-primary-skin-cancer-after-cancer-treatment/), [The UK very high risk breast screening protocol after chest radiotherapy](https://onco.cc/terms/rejuv-second-uk-very-high-risk-breast-screening/), [Thyroid cancer after neck radiotherapy, and whether to look for it](https://onco.cc/terms/second-primary-thyroid-after-neck-radiotherapy/), [What is not a second cancer: recurrence, metastasis and field cancerisation](https://onco.cc/terms/rejuv-second-what-is-not-a-second-cancer/)
- cancers: [Childhood cancers (all types)](https://onco.cc/cancers/childhood-cancers/), [Hodgkin lymphoma](https://onco.cc/cancers/hodgkin-lymphoma/), [Sarcomas (soft tissue, bone, GIST)](https://onco.cc/cancers/sarcoma/)
- fronts: [Radiation Therapy](https://onco.cc/fronts/radiation/), [Recovery & Rejuvenation](https://onco.cc/fronts/rejuvenation/)
- technologies: [Clonal haematopoiesis after cancer treatment](https://onco.cc/technologies/rejuv-age-clonal-haematopoiesis-after-therapy/), [Frailty and late effects in survivors](https://onco.cc/technologies/rejuv-age-frailty-and-late-effects/), [Proton therapy](https://onco.cc/technologies/proton-therapy/), [Second cancers after childhood cancer: the risk by treatment, and why it is falling](https://onco.cc/technologies/rejuv-paed-second-cancers/), [Survivorship care and late-effects surveillance](https://onco.cc/technologies/survivorship-care-plan/)

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