Evidence reviews for adjuvant systemic therapy planning: Early and locally advanced breast cancer: diagnosis and management

Excerpt

Current UK recommendations in the previous guideline CG80 (NICE 2009), and from the Royal College of Pathologists (RCPath, 2016), state that oestrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2) biomarkers should be assessed in all invasive breast cancers. This biomarker analysis can provide important prognostic and predictive information to help direct further adjuvant management breast cancer after surgery.

ER positivity in breast cancers can predict a potential response to endocrine-based treatments and these cancers are known to have an overall better prognosis than ER-negative cancers. Progesterone receptor (PR) is from the same family of molecules as ER, but CG80 recommended not to routinely test all breast cancers for PR as, at the time, there was no strong evidence to support PR being predictive of a response to endocrine therapy (despite being independently prognostic for relapse-free survival and overall survival).

The co-expression of ER and PR does vary between breast cancers. Whilst the majority of breast cancers which are ER positive are also PR positive, many are PR negative, and studies have now shown these to have a worse prognosis and to be less responsive to endocrine therapies. Some people have breast cancers that are negative for each of ER, PR and HER2. As none of the 3 biomarkers are expressed in these cancers, they are conventionally referred to as ‘triple negative’ and are associated with a poor prognosis without treatment, but the cancer may respond well to certain forms of chemotherapy.

The purpose of this review question is to determine if establishing PR status affects planning for adjuvant chemotherapy.

Planning adjuvant treatment is complex and incorporates a variety of prognostic and predictive factors. In order to identify which people would benefit from adjuvant therapy, a number of prognostic tools have been developed. These take into account a number of factors such as age, comorbidities, tumour staging and biomarkers, and assess the risk of an individual person developing recurrent disease and/or dying within 10 years when receiving a specific treatment. These prognostic tools can be used jointly by the person and their doctor to determine the most appropriate adjuvant treatment (chemotherapy, endocrine therapy, or no therapy).

The aim of this review is to determine which of the currently available prognostic tools is most reliable at correctly predicting survival and the benefits of adjuvant treatment.

See Table 3 for a description of the prognostic tools included in this review.