Endoscopic mastectomy meta-analysis: commentary

Correspondence to: Kefah Mokbel (email: kefahmokbel2@gmail.com)

The London Breast Institute

Princess Grace Hospital

Exploring psychological consequences for BRCA+ women in the post-Covid era

Whilst the global female population has a 12.5% overall lifetime risk of developing breast cancer and a 1.3% risk of ovarian cancer (Howlader et al), the risk for those with a pathogenic BRCA1 or BRCA2 mutation is 60-70% and 10-20% respectively (van Egdom et al). BRCA1 mutation carriers have a particularly high incidence of triple-negative breast cancer (TNBC) (Greenup et al) for which treatment options are more limited and always include chemotherapy (Bianchini et al; Collignon et al). 

In the NHS, asymptomatic women with at least a 10% estimated chance of having a BRCA mutation are offered testing (NICE).  Knowing you are at high risk of breast cancer and the increased likelihood of TNBC is a well-documented  cause of anxiety (Wenzel et al) and many women describe having a BRCA gene mutation as living with a ‘ticking time bomb’. Bilateral mastectomy with or without reconstruction is the only proven method of drastically decreasing risk and can improve quality of life (McCarthy et al) and decrease anxiety (Rebbeck et al) for correctly selected cases, despite its potential negative outcomes (Gahm et al). 

Invasive lobular breast cancer is the second most common histological subtype and constitutes around 10-15% of all breast cancer. It is recognized by a peculiar diffuse growth pattern and disseminated spread of cancer cells contributing to diagnostic delay and difficulties in detecting the primary tumors by mammography and nodal metastasis by axillary ultrasound. Consequently, although invasive lobular breast cancer mainly displays a favorable luminal A molecular subtype, it is often diagnosed at a higher stage than invasive cancer of no special type. Despite these characteristics, histopathological subtype is not accounted for in Clinical Guidelines, in contrast to the molecular subtypes. In the BJS publication “The St. Gallen 2019 Guidelines understage the Axilla in Lobular Breast Cancer: a Population-Based Study” by Ulrik Narbe and co-authors, we have elaborated on the consequences for patients with invasive lobular cancers if completion axillary clearance would be omitted in patients with 1-2 nodal metastases.

For the breast surgeon, lobular cancer poses a challenge to surgery of the breast and to the axilla. Large tumor size and diffuse infiltrating margins are associated with an increased risk of positive margins after breast conserving surgery and in breast centers where MRI is available, complementary imaging is recommended ahead of primary surgery. Still a larger proportion of patients (66%) with lobular cancer undergo a mastectomy compared to other histological subtypes (43%) according to our registry study, supporting previous publications. So the dogma of de-escalating breast surgery from mastectomy to partial mastectomy in lobular cancer is challenging, keeping in mind that positive resection margins is a mandatory quality criteria in most centers pushing the choice of initial surgery towards upfront mastectomy.

Axillary surgery is moving towards de-escalation of surgical interventions for patients with 1-2 sentinel node metastases after the results of the Z0011 trial have been implemented worldwide and clearly supports that omission of completion axillary dissection is non-inferior provided the inclusion criteria for the trial is fulfilled. The Z0011 criteria for omission of completion axillary dissection is restricted to patients undergoing breast-conserving surgery, and is thus not applicable for lobular cancers operated by mastectomy. The St. Gallen 2019 guidelines extended the indication for abstaining completion axillary dissection to all patients of any tumor size irrespective of type of breast surgery. In addition, the guidelines recommended that the decision on adjuvant chemotherapy for luminal A-like tumors should include nodal staging and patients with 4 or more nodal metastasis (nodal stage II) were recommended adjuvant chemotherapy. For these patients there is hitherto no data on the role of genomic tests for risk stratification until the results of OPTIMA trial are presented. In this paper, we present data from the National Swedish Quality Registry with prospectively collected data retrieved from the period when a completion axillary clearance for patients with sentinel node metastases was recommended. We found a strong association between invasive lobular breast cancer and nodal stage II disease independent of other determinants such as tumour size.