Long-term cosmetic changes after breast-conserving treatment of patients with stage I–II breast cancer and included in the EORTC ‘boost versus no boost’ trial

• Published in: Annals of oncology Vol. 23; no. 10; pp. 2591 - 2598
• Main Authors: Immink, J.M., Putter, H., Bartelink, H., Cardoso, J.S., Cardoso, M.J., van der Hulst-Vijgen, M.H.V., Noordijk, E.M., Poortmans, P.M., Rodenhuis, C.C., Struikmans, H.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-10-2012; Oxford University Press
• Subjects: Antineoplastic agents; Biological and medical sciences; boost; breast cancer; Breast Neoplasms - surgery; breast-conserving therapy; cosmetic results; Female; Gynecology. Andrology. Obstetrics; Humans; Mammary gland diseases; Mastectomy, Segmental; Medical sciences; Pharmacology. Drug treatments; radiotherapy; Tumors; cosmetic results; radiotherapy; breast cancer; boost; breast-conserving therapy; Cosmetic; Human; Breast disease; Patient; Early stage; Breast cancer; Malignant tumor; Radiotherapy; Long term; Mammary gland diseases; Treatment; Breast; Clinical trial; Mammary gland; Comparative study; Cancer; European Organization for Research and Treatment of Cancer
• ISSN: 0923-7534; 1569-8041
• DOI: 10.1093/annonc/mds066

In breast cancer treated with breast-conserving radiotherapy, the influence of the boost dose on cosmetic outcome after long-term follow-up is unknown.
We included 348 patients participating in the EORTC ‘boost versus no boost’ mega trial with a minimum follow-up of 6 years. Digitalised pictures were analysed using specific software, enabling quantification of seven relative asymmetry features associated with different aspects of fibrosis.
After 3 years, we noted a statistically significantly poorer outcome for the boost patients for six features compared with those of the no boost patients. Up to 9 years of follow-up, results continued to worsen in the same magnitude for the both patient groups. We noted the following determinants for poorer outcome: (i) boost treatment, (ii) larger excision volumes, (iii) younger age, (iv) tumours located in the central lower quadrants of the breast and (v) a boost dose administered with photons.
A boost dose worsens the change in breast appearance in the first 3 years. Moreover, the development of fibrosis associated with whole-breast irradiation, as estimated with the relative asymmetry features, is an ongoing process until (at least) 9 years after irradiation.