Résumé
The effectiveness of adjuvant radiotherapy at the loco-regional level in the treatment of breast cancer significantly improves loco-regional control and survival. However, there are different opinions about the dose and the number of fractions to be prescribed from one institute to another. For the irradiation of the whole breast or the chest wall, the hypofractionation regimen including a total dose of 28.5 Gray (Gy) delivered in 5 fractions over 5 weeks, FAST scheme, is the standard of care for this type of irradiation for elderly patients, while 40 Gy in 15 fractions over 3 weeks is used for younger patients (START-B scheme).Nevertheless, the gold standard for lymph node irradiation remains the START-B scheme.
Controversy is found in lymph node irradiation, mainly due to the lack of prospective and retrospective evidence. Due to the Covid-19 crisis, the department of Radiation Oncology CHU UCL Namur, site Saint-Elisabeth decided to irradiate younger patients (3 65-year-old instead of 3 75-year-old), including nodal irradiation according to the FAST scheme, even if this is not the standard of care in this hospital. Aim: The aim of this retrospective study is to prove that the toxicity associated to the loco- regional level, with the FAST regimen in 5-fraction, is not superior to the toxicity defined by the START-B scheme. Methods: Two cohorts of patients over 65 years of age are analysed retrospectively, one including the FAST scheme, the other including the START-B scheme. Both cohorts include patients treated between 2018 and 2021 at the Saint Elisabeth Hospital. The patient’s data are transcribed into the RedCap software and analysed by a biostatistician. The baseline characteristics of patients included are compared, and a list of possible adverse events is used to analyse the toxicity of these two regimens of radiation. Then the progression-free survival and the overall survival are analysed in both groups as secondary endpoints. Analysis: 221 patients are included in the study, 87 patients in the FAST group (median age of 78 years old) versus 118 patients (median age of 68 years old) in the START-B group. The most reported adverse event in the two groups is acute dermatitis with a higher proportion in the START-B group: (81.4% versus 66.6% in the FAST group). The overall survival and the progression-free survival tend to be superior in the START-B group, a younger population.
Conclusion: The toxicity of the FAST regimen does not demonstrate greater toxicity than the toxicity of the START-B regimen, when it used at the lymph node level in younger patients than usual.
| la date de réponse | 6 mars 2023 |
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| langue originale | Anglais |
| L'institution diplômante |
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| Superviseur | Vincent M. Remouchamps (Promoteur) & Anne-Emmanuella Yeo (Jury) |