professionals of Puerta del Mar University Hospital in Cádiz have presented the results of an observational study conducted over 15 years on the effectiveness of a medicine (adjuvant trastuzumab) in patients with breast cancer.
The investigation has been coordinated by Jose Manuel Baenasection chief of the Medical Oncology Service of this center and provincial coordinator of the onco-hematology program of the Institute for Biomedical Research and Innovation of Cádiz (INiBICA).
Breast cancer is the most frequent tumor in women, with a progressive increase in new cases (among others, due to early detection programs) but also with improved survival, thanks to the effectiveness of new therapies. However, when talking about breast cancer It must be taken into account that there are different subtypes and from the molecular point of view three stand out: luminal, triple negative and HER2.
Precisely the latter, which corresponds to 15-20% of cases, is associated with greater aggressiveness and worse prognosis, which is why the Medical Oncology service of Hospital Puerta del Mar designed an observational study, in which the health results are analyzed, in terms of survival and toxicity in the last fifteen years, of those patients who received trastuzumab, a humanized monoclonal antibody against said over-expression of the HER2 oncogene, in this type of of localized tumors and since its approval in Spain in 2006.
It is drugdespite having shown in the main clinical trials a clear increase in survival when combined with chemotherapycan present an adverse effect that is essential to identify, its cardiac toxicity.
For this reason, ultrasound checks of the heart are performed quarterly on the patients and, in the event of detecting suspicious signs of heart damage, the administration of the drug is interrupted. However, in most cases, this toxicity is reversible and the drug can be resumed when cardiac function returns to normal.
The administration of this treatment takes place every three weeks for a year, considering it optimal to receive at least 17 cycles.
Out of a total of 1,479 women treated in Cádiz between January 2006 and December 2020, 275 (20%) had HER2 overexpression. The median age was 53 years and practically all of them had a good quality of life and few or no additional diseases.
Patients older than 65 years and those who developed cardiac toxic effects were the most likely to not complete the year of treatment. Of the 25% of women who discontinued trastuzumabthe vast majority did so due to cardiac toxicity, although they generally presented asymptomatically in ultrasound check-ups and this adverse effect was observed more frequently in those who also received radiotherapy.
However, the main treatment in these tumors localized is surgery and, depending on its characteristics, chemotherapy and trastuzumab it is decided to administer it before it with the intention of reducing the size of the lesion or after (adjuvant) to prevent its relapse. Very positive results are presented in adjuvant and neoadjuvant treatment, since practically half of those who received trastuzumab prior to surgery obtained a complete pathological response of the tumor at the time of the surgical procedure.
Regarding the events, 9.16% developed metastases and 9.4% died, most of them due to their own breast cancer. However, the survival analysis yields very encouraging results, 88% had not suffered a recurrence of the tumor at 5 years and between 93% and 88% were still alive at 5 and 10 years respectively, very encouraging figures to follow. advancing in the investigation of therapies that allow patients with breast cancer to have greater survival, maintaining a good quality of life.
One of the strengths of this study of the Puerta del Mar Hospital in Cádiz is that it is the first in Spain with such detailed data on the effectiveness of adjuvant trastuzumab and its cardiac toxicity, with extensive follow-up of up to 15 years and in a real population from their own consultations, so these results can be very valuable information. so that other centers can compare and promote new studies.
The results of the study have been presented by Dr. Baena and the resident Jaime Lluch in a clinical session attended by different associations of patients from the province, such as the Association Against Cancer of Trebujena, the Association of Women with Cancer Bahía, the Cadiz Association Against Breast Cancer, the Association for the Fight Against Cancer of Rota and the Spanish Association against Cancer. During said event, the Trebujena Cancer Association also made a donation to INiBICA to promote research.
