Breast cancer (BC) is the most common cancer in women. In western society many women are living with BC, with symptoms after treatment and the risk of recurrence. When a woman develops cancer all her relationships are affected. Today the survival rate is very high with nine out of ten surviving for five years, meaning that there are many lives affected by the out-come of BC.

The most important prognostic factor in BC is the status of the lymph nodes in the axilla. However, surgery in the axilla is associated with significant arm morbidity. Thus, there is an urgent need to deescalate the effect of axillary surgery. This thesis investigates how to perform oncologically safe surgery with as little harm as possible.

The main aim was to identify factors for predicting non-sentinel node metastases and investigate different methods for sentinel node (SN) identification in the primary and recurring BC setting as well as to explore patients’ trajectory through BC treatment including axillary surgery. Furthermore, to reduce unnecessary suffering due to axillary surgery.

The first study aimed at identifying the clinicopathological predictive factors that are responsible for non-SN metastases. Using data from a large cohort from the National Quality Register for Breast Cancer (NKBC), we identified factors associated with non-SN metastasis. The findings showed how to differentiate between those with a risk for non-SN metastasis and in need of further axillary surgery and those with only a limited spread to the SN. A logistic regression model revealed statistically significant factors such as proportion of SN with macro metastases detected at SN biopsy, tumour size, HER2 positivity, lymphovascular invasion and multifocality as strong factors for non-SN metastasis. These factors were incorporated in a nomogram for predicting the risk of non-SN metastasis to avoid unnecessary axillary lymph node dissection.

In the second study the aim was to determine whether scintigraphy imaging can improve the detection rate for SN, SN metastases and non-SN metastases. The study explored which technique is best for identifying the SN, in order to better visualize it and thus facilitating the surgery procedure. The difference in SN outcome using the conventional radioisotope technique, Technetium-99m (Tc99), when adding scintigraphy to the gamma probe and blue dye was also compared. The findings showed a small difference of 2.3% in favour of adding scintigraphy images. However, it is unclear as to whether this will have any effect in the clinical setting.

The third paper adopted a person-centred approach to understand how healthcare professionals can facilitate women subjected to BC treatment including axillary surgery. An interview study was conducted using a phenomenological hermeneutical method. The main finding was that the women were in a state of acceptance and adaptation to their situation. When healthcare professionals provided structure and consistency, the women’s treatment and lived experience made sense. Uncertainty occurred when the women became lost in their own sense-making process, leading to low self-efficacy.

The fourth study was a feasibility study to identify better options for women with recurrence. An investigation of BC patients with recurrence and earlier axillary surgery was conducted to scrutinize if it is feasible to identify the SN with the magnetic tracer, superparamagnetic iron oxide, SPIO, com-pared to conventional methods with radioisotope (Tc99) and blue dye. The study was conducted at two hospitals, Sahlgrenska University Hospital and Linköping University Hospital. The findings showed that SPIO had a higher detection rate and a concordance rate of 92%. In conclusion, SPIO is a tracer with a smoother transition and easier handling eliminating the need for the radioisotope which has a short half-life and of which there is a limited global supply.

To conclude, this thesis emphasises the importance of being able to fine tune the factors that point to individual risk factors for non-SN metastases and transit to the next SN tracer with the magnetic technique. A person-centred approach during treatment and follow-up is warranted to support self-management among women with BC.