ESTRO 2022

Session Item

Monday

May 09

10:30 - 11:30

Mini-Oral Theatre 2

20: Breast

Co-Chair: Nienke Hoekstra, The Netherlands;

Chair: Wilfried Budach, Germany

Session Code: 3260

Session Type: Mini-Oral

Track: Clinical

CANTO-RT: Skin toxicities evaluation of prospective cohort of irradiated patients for breast cancer

sofiane allali, France

Presentation Number: MO-0800

Abstract

Abstract Title:

CANTO-RT: Skin toxicities evaluation of prospective cohort of irradiated patients for breast cancer

Authors:

sofiane allali¹, Matthieu Carton², Thomas Sarrade³, Sibille Everhard⁴, Ophélie Querel⁴, Sofia Rivera⁵, Karine Peignaux⁶, Phillippe Guilbert⁷, Claire Chara-Brunaud⁸, Julien Blanchecotte⁹, Alain Labib³, David Pasquier¹⁰, Séverine Racadot¹¹, Céline Bourgier¹², Geffrelot Julien¹³, Paul Cottu¹⁴, Ines Vaz-Luis¹⁵, Youlia Kirova¹

¹Curie Paris, radiation oncology, Paris, France; ²Curie Paris, biostatistics department, Paris, France; ³Curie St Cloud, radiation oncology, Saint Cloud, France; ⁴Unicancer, Unicancer, Paris, France; ⁵Institut Gustave Roussy, radiation oncology, villejuif, France; ⁶Centre Georges-François Leclerc, radiation oncology, Dijon, France; ⁷Jean Godinot, radiation oncology, Reims, France; ⁸Institut de cancérologie de Lorraine, radiation oncology, Vandoeuvre les Nancy, France; ⁹Institut de Cancérologie de L'ouest - Paul Papin , radiation oncology, Angers, France; ¹⁰Centre Oscar Lambret, radiation oncology, Lille, France; ¹¹Centre Léon Berard, radiation oncology, Lyon, France; ¹²ICM, radiation oncology, Montpellier, France; ¹³Centre François Baclesse, radiation oncology, Caen, France; ¹⁴Curie Paris, oncology , Paris, France; ¹⁵Institut Gustave Roussy, biostatistics department, Villejuif, France

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Purpose or Objective

Skin damage is the most common and important toxicity during and after radiotherapy (RT). Its assessment and understanding of the factors influencing its occurrence, is a major issue in the management of patients irradiated for an early breast cancer (eBC).

Material and Methods

We included 3480 patients with stage I-III eBC, treated with RT and with collected raw RT data from 2012-2017 in 10 cancer centers from the prospective CANTO cohort (NCT01993498) in the CANTO-RT study.

We are focus on specifical skin toxicities: erythema, fibrosis, telangectasia . These toxicities were assessed at 3–6 (M0), 12 (M12) and 36 (M36) months after acute treatment using CTCAE V4.0.

The RT-related variables were independent variables. Multivariable logistic regression models assessed associations between RT-related variables and skin toxicities of interest.

Results

CANTO-RT patients had a median age of 56.8 years and a mean BMI of 26 kg/m². The majority had SBR grade 1-2, T1-2, RH+/HER2- tumours. Most patients (80%) had conservative surgery and 52.7% received chemotherapy (CT). All the patients received RT mainly normofractionated 50Gy in 25 fractions, in 3D, with a boost of 16Gy in 8fractions.

The prevalence of toxicities of interest varied over time, at M0, 41.1% of patients had erythema while 24.8% of patients had fibrosis. At M12 and M36, the prevalence of erythema decreased from 8.8% to 2.9% respectively while fibrosis remains stable from 25.1% to 22.5%. The prevalence of telangiectasia increases from 1% to 7.1% from M0 to M36. After adjustments, at M0 and M12, we showed a statistically significant association between the occurrence of skin erythema and obesity OR: 1.3 [1.09; 1.54] (p <0.003); the presence of axillary dissection (p <0.003); the type of surgery (p <0.001); the use of taxane-based CT (p <0.005) and the 3DvsIMRT irradiation technique OR: 0.42 [0.28; 0.62] (p <0.001). However, no RT factors were statistically related to erythema from M12.

Regarding fibrosis, a statistically significant association is found, at M0, with age at diagnosis (p <0.018), obesity (OR: 1.44 p <0.001), tobacco (OR: 1.4 p <0.008), and the use of boost OR: 1.61 [1.24; 2.11] (p <0.001). Only obesity and the type of surgery received by the patient remained statistically significant at M12 and M36. The evolution of the principal skin toxicities is given in figure 1.

Obesity and age at diagnosis represented at M12 and M36 a risk associated with the onset of telangiectasias.

Conclusion

In this study we identified several risk factors for acute and late skin toxicity such as obesity in the occurrence of skin erythema, fibrosis or telangiectasia. The use of a boost was mainly related to the occurrence of fibrosis while the use of IMRT-type technique decreased the occurrence of skin erythema (radiodermatitis). The knowledge of its predictive factors allows a personalized management of the patient by adapting our treatments and our monitoring according to these different factors.