How is adjuvant hormone therapy?

​

In premenopausal women with luminal tumors, the use of tamoxifen remains a standard recommendation despite the favorable results with the use of AIs and suppression of ovarian function (FOS) with the LHRH analogues.  However, the association between Tamoxifen and SFO remains uncertain. In a randomized study that included women with small tumors and free armpits, there was no benefit in overall survival and disease-free survival from adding SFO to Tamoxifen. Still, there was a higher incidence of adverse events and reduced quality of life in the group of women undergoing OFS.

In recent years, however, several studies have observed superiority of AIs over tamoxifen in postmenopausal adjuvant HT. A meta-analysis comparing AIs to Tamoxifen observed a relative reduction of 23% in the risk of recurrences with AIs, with a slight increase in survival and a reduction in recurrences. However, direct comparison between AI monotherapy and sequential regimens did not result in differences in overall survival or disease-free survival.

It should be noted that the benefit of AIs over tamoxifen in postmenopausal women was observed both in ductal carcinomas and in lobular carcinomas, although the magnitude of this benefit is greater among those with lobular neoplasia.

In general, aromatase inhibitors are well tolerated drugs, with a lower incidence of vaginal bleeding, endometrial cancer and thromboembolic events compared to tamoxifen. However, AIs can increase the risk of cardiovascular events, bone loss and pathological fractures, in addition to arthralgia and musculoskeletal symptoms. Therefore, knowledge of the safety profile and adverse events related to these medications can contribute to decision making about the most appropriate TH protocol for each patient.

When to use Extended Adjuvant Hormone Therapy?

​

The use of tamoxifen for five years is recommended for premenopausal women. For those in post-menopause, it is recommended to use an aromatase inhibitor (AI) for five years or the switch modality (alternation) until reaching the age of five. Ten-year extended treatment with AI is not recommended for postmenopausal patients who used AI as a first-line or switch modality, however, extended AI use after 5 years of tamoxifen can be considered individually.

Additionally, the use of tamoxifen extended for ten years should be considered individually in patients with tumors at high risk of recurrence, after the assessment of risks and benefits by the medical team, especially in positive lymph nodes.

Breast cancer index is the test that analyzes the behavior of seven genes to predict the risk of hormone-positive and HER2-negative breast cancer relapse after five years. It may also help to decide whether hormone therapy or hormone therapy needs to be extended for another five years, making a total of 10 years.

​

What types of radiotherapy?

​

External or conventional radiation therapy is the most common type to treat breast cancer. This treatment consists of irradiating the target organ with fractionated doses. The patient does not feel anything during the application, which lasts only a few minutes a day.

The areas that should be irradiated depend on the type of surgery performed (mastectomy or breast-conserving surgery) and whether the lymph nodes were (or not) involved:

If the patient underwent breast-conserving surgery, the entire breast will be irradiated to prevent recurrence in this region.

If cancer has been diagnosed in the axillary lymph nodes, this area is also irradiated. In some cases, the area treated may also include the supraclavicular lymph nodes and the internal breast lymph nodes.

Radiotherapy is given 5 times a week (Monday to Friday) for about 5 to 6 weeks. But recently, new modalities have made it possible to reduce the number of days of application (hypofractionation), to give higher doses for a shorter period. There are different types of accelerated breast irradiation:

Hypofractionated Radiotherapy. In this approach, radiotherapy is typically given in high doses for just 3 weeks. In women treated with breast-conserving surgery and without axillary lymph node disease, this regimen is as promising in preventing relapse as a 5-week treatment. Which can also lead to fewer side effects in the short term. In a newer approach being studied, larger doses of radiation are given each day, but the radiation cycle is reduced to just 5 days.

Intraoperative radiotherapy. In this approach, a single high dose of radiation is administered in the operating room right after breast-conserving surgery. This technique requires special equipment and is not widely available.

​

​

​

​

                                                                 external radiotherapy

​

Is there a superiority in the dose distribution in the case of breast irradiation with intensity modulated radiotherapy (IMRT) in relation to conventional and conformal radiotherapy?

​

  IMRT is the modality that presents the best dose coverage in the treatment target (breast) when compared to the conformal and conventional techniques. In addition, IMRT significantly reduces doses to organs at risk. The dose decrease in contralateral breast can be up to 50%, which can reduce the likelihood of radio-induced breast cancer especially in young women. This was observed in relation to other structures such as the heart and lungs (ipsilateral and contralateral), which may be associated with a reduced risk of lung disease and chronic heart disease. This benefit was also demonstrated in patients undergoing mastectomy and plastron adjuvant radiotherapy