Efficacité et sécurité de la technique de radiothérapie mammaire avec complément d’irradiation concomitant : analyse de 121 cas traités à l’institut de cancérologie de Lorraine

Axillary pathologic response after neoadjuvant chemotherapy and surgery according to breast cancers subtypes and survival impact

PURPOSE

To retrospectively assess the rate of pathologic complete response in the axilla according to breast cancer biologic subtypes, and to study the impact of nodal response on survival.

METHODS

Inclusion criteria were all T-stage breast cancers with initial lymph node involvement, non-metastatic, treated with neoadjuvant chemotherapy followed by surgery with axillary lymph node dissection, managed at the George-François Leclerc Cancer Center in Dijon, France, between 2000 and 2018.

RESULTS

Among 437 patients included, the rate of complete nodal response rate varied according to tumor subtypes: 69.4% in Hormone Receptors (HR)-/HER2-positive, 47.4% in HR-/HER2-negative, 46.7% in HR+/HER2-positive, 8.5% in HR+/HER2-negative. By multivariate analysis, the factors significantly associated with complete nodal response were HER2-positive profile (OR 4.48 [2.14-9.65], P<0.001 if HR+; OR 8.02 [3.54-18.74], P<0.001 if HR-), triple negative tumors (OR 3.01 [1.40-6.58], P=0.005), SBRIII grade (OR 6.85 [2.28-29.58], P=0.002) and breast complete response (OR 18.69 [9.67-38.53], P<0.001). Five-year recurrence rates were 15.7% in ypN0, 23% in ypN1, 41.2% in ypN2, 50% in ypN3 patients (P<0.001). Five-year overall survival rates were 92.2% in ypN0, 85.7% in ypN1, 72.2% in ypN2, 65.4% in ypN3 patients (P<0.001).

CONCLUSION

The impact of nodal response on survival was significant. Pathologic complete response in the axilla appears to be a good surrogate marker of long-term outcome in patients treated for these cancers.

Should the management of radiation therapy for breast cancer be standardized? Results of a survey on current French practices in breast radiotherapy

Background

Breast cancer is the most frequent cancer in women in France. Its management has evolved considerably in recent years with a focus on reducing iatrogenic toxicity. The radiotherapy indications are validated in multidisciplinary consultation meetings; however, questions remain outstanding, particularly regarding hypofractionated radiotherapy, partial breast irradiation, and irradiation of the internal mammary chain and axillary lymph node area.

Materials and methods

An online survey was sent to 47 heads of radiotherapy departments in France. The survey consisted of 22 questions concerning indications for irradiation of the supraclavicular, internal mammary and axillary lymph node areas; irradiation techniques and modalities; prescribed doses; and fractionation.

Results

Twenty-four out of 47 centers responded (response rate of 51%). This survey demonstrated a wide variation in the prescribed dose regimen, monoisocentric radiotherapy, and indications of irradiation of the lymph node areas.

Conclusion

This survey provides insight into the current radiotherapy practice for breast cancer in France. It shows the need to standardize practices.

Intensity modulated radiation therapy with simultaneous integrated boost in early breast cancer irradiation. Report of feasibility and preliminary toxicity

PURPOSE

To investigate the feasibility and tolerance in the use of adjuvant intensity modulated radiation therapy (IMRT) and simultaneous integrated boost in patients with a diagnosis of breast cancer after breast-conserving surgery.

PATIENTS AND METHODS

Between September 2011 to February 2013, 112 women with a diagnosis of early breast cancer (T1-2, N0-1, M0) were treated with IMRT and simultaneous integrated boost after breast-conserving surgery in our institution. A dose of 50Gy in 25 fractions was prescribed to the whole breast and an additional dose of radiation was prescribed on the tumour bed. A dose prescription of 60Gy in 25 fractions to the tumour bed was used in patients with negative margins after surgery, whereas if the margins were close (<1mm) or positive (without a new surgical resection) a dose of 64Gy was prescribed. All patients were followed with periodic clinical evaluation. Acute and late toxicity were scored using the EORTC/RTOG radiation morbidity score system. Both patient and physician recorded cosmetic outcome evaluation with a subjective judgment scale at the time of scheduled follow-up.

RESULTS

The median follow-up was 28 months (range 24-40 months). The acute skin grade toxicity during the treatment was grade 0 in 8 patients (7%), grade 1 in 80 (72%), grade 2 in 24 cases (21%). No grade 3 or higher acute skin toxicity was observed. At 12 months, skin toxicity was grade 0 in 78 patients (70%), grade 1 in 34 patients (30%). No toxicity grade 2 or higher was registered. At 24 months, skin toxicity was grade 0 in 79 patients (71%), grade 1 in 33 patients (29%). No case of grade 2 toxicity or higher was registered. The pretreatment variables correlated with skin grade 2 acute toxicity were adjuvant chemotherapy (P=0.01) and breast volume ≥700cm(3) (P=0.001). Patients with an acute skin toxicity grade 2 had a higher probability to develop late skin toxicity (P<0.0001). In the 98% of cases, patients were judged to have a good or excellent cosmetic outcome. The 2-year-overall survival and 2-year-local control were 100%.

CONCLUSION

These data support the feasibility and safety of IMRT with simultaneous integrated boost in patients with a diagnosis of early breast cancer following breast-conserving surgery with acceptable acute and late treatment-related toxicity. A longer follow-up is needed to define the efficacy on outcomes.