Post treatment mastalgia is a common complaint after breast cancer treatment. The current study found that 36% of patients complained of post treatment mastalgia. Only two patients (0.3%) diagnosed with a second breast cancer, however, had ever complained of post treatment mastalgia prior to their second diagnosis. In addition, neither patient had mastalgia at the time of their diagnosis.
Several studies have demonstrated that after treatment of breast cancer, the risk of breast pain or post treatment mastalgia is between 20-68% (Geving Anderson, et al. 2011; Bruce, et al 2012; Bruce, et al. 2014; Schreiber, et al. 2013). The pain is common and can occur after either breast conservation or mastectomy. The breast pain can persist for 12 years, become a chronic complaint, and sometimes may also be musculoskeletal pain (Bovbjerg, et al. 2019; Lundstedt, et al. 2012; Bell, et al. 2014; Forget, et al. 2020; Macdonald, et al 2005). Treatment related factors include radiation therapy, chemotherapy, younger age at diagnosis, axillary node dissection/clearance and lymphedema (Geving Anderson, et al. 2011; Bruce, et al. 2014; Lundstedt, et al. 2012; Bell, et al. 2014; Peuckmann, et al. 2009; Gärtner, et al. 2009). Bell, et al. reported that while breast cancer treatment contributes to breast pain, it is clear that there is no simple mechanical issue or single treatment factor as the cause (Bell, et al. 2014).
Patients fear that mastalgia is a sign of breast cancer recurrence. Thirteen studies in different populations from several countries have shown no association of mastalgia with an initial diagnosis of breast cancer. Of 13,183 patients only 106 (0.8%) were found to have breast cancer (Altintas, et al, 2018; Holbrook, et al. 2020; Cho, et al. 2017; Owen, et al. 2019; Chetlen, et al. 2017; Duikm, et al. 1998; Leddy, et al. 2013; Mema, et al. 2019; Fonseca, et al. 2019; Noroozian, et al 2015; Masroor, et al. 2009; Howard, et al. 2012). Interestingly, most patients who complained of post treatment mastalgia did not have pain prior to their diagnosis. Of the current patients who complained of post treatment mastalgia, only 2.6% (14/548) had breast pain prior to their initial diagnosis and only two patients had ipsilateral breast pain. Consistent with prior to an initial diagnosis of breast cancer, post treatment mastalgia was not associated with diagnosis of a second breast cancer (CW/IBTR/CBC). Factors that were associated with diagnosis of a second breast cancer included higher stage of cancer and triple negative breast cancer. In addition, as could be expected, not having undergone recommended adjuvant chemotherapy, radiation therapy, and endocrine or targeted therapy were also associated with a second breast cancer diagnosis (Table 4 and 5).
There has been recent substantial growth in neurobiological research on pain and emotion. There is a subcortical circuit that governs defensive responses, and this circuit involves the nonconscious processing of stimuli that underlie emotional states associated with persistent pain. Repeated fear experiences can elicit anticipatory anxiety, thereby contributing to persistent pain (Lumley, et al 2011). The belief that mastalgia indicates cancer recurrence could be considered a continued repeated fear experience.
The majority of patients (57% = 310/548) complained of post treatment mastalgia at more than one follow up clinic visit. These patients substantially overestimated their risk of breast cancer recurrence at 52%. Unfortunately, the belief that mastalgia indicates cancer is common in breast cancer survivors with persistent breast pain. Bovbjerg, et al. found that survivors also had higher levels of general anxiety, pain catastrophizing, and worry (Bovbjerg, et al. 2019). One patient in the current study complained of breast pain at seven consecutive follow up visits over a 3 year period including several Emergency Department visits. Despite undergoing standard follow up imaging and being reassured during each visit, the patient insisted that the post treatment mastalgia was a sign that she had breast cancer recurrence. The patient did not have a second breast cancer and was eventually seen by a psychiatrist and diagnosed with illness anxiety disorder for which she started cognitive behavioral therapy (Scarella, et al 2019). Bovbjerg, et al. similarly concluded that perceived risk of breast cancer and worry that pain may indicate cancer as important targets for intervention (Bovbjerg, et al 2019; Porter, et al. 2011). Augmentation of positive emotional states or relief of fear and anxiety generally have been found to reduce pain (Lumley, et al. 2011; Franklin 1998). A study by Bruce, et al. found that psychological robustness or dispositional optimism and positive affect may also have a favorable effect on post-operative breast pain severity (22). Pain is a subjective, complicated patient-reported phenomenon likely multifactorial and involving preoperative patient psychological factors (Bruce, et al. 2012; Schreiber, et al. 2013; Macdonald, et al. 2005; Törer, et al. 2010). Breast cancer patients experience anticipatory psychological distress prior to their diagnosis of breast cancer and prior to their cancer operation (Schnur, et al. 2008; Montgomery, et al 2010). Other studies have found that patients with greater preoperative emotional distress, depression and anxiety scores have significantly more clinically meaningful and chronic postoperative pain (Bruce, et al. 2014; Törer, et al. 2010; Katz, et al. 2005). Therefore it is possible that patients with more fear and worry about their prognosis may have more post treatment pain.
Schreiber, et al. found that patients with persistent postmastectomy pain were more likely to catastrophize in response to pain (Schreiber, et al. 2013). This study provides reassurance that post treatment mastalgia is not associated with breast cancer recurrence. Worry that breast pain indicates cancer is a common belief and source of distress for patients. Since post treatment mastalgia can become a chronic problem and a factor which lowers quality of life for patients (Macdonald, et al. 2005; Peuckmann, et al 2009), the current findings may help lessen worry about pain as a patient-reported outcome.
The findings of the current study that post treatment mastalgia is not a sign of breast cancer recurrence is also relevant because it makes interval mammography and other imaging unnecessary. It is particularly important to avoid unnecessary mammography in breast cancer survivors with persistent breast pain. A study by Shelby, et al found that breast pain and mammography related anxiety were associated with not returning for a mammogram (Shelby, et al 2012). Therefore post treatment mastalgia could inadvertently contribute to decreased compliance with recommended imaging during follow up.
One limitation of this study is that it is a retrospective review from one institution. The retrospective design of the current study, however, did allow review of patients diagnosed with a second breast cancer who presented with all other complaints to ensure that no patients who complained of post treatment mastalgia were missed.
Post treatment mastalgia is a common complaint after breast cancer treatment. Many patients fear that this symptom indicates cancer recurrence. This study demonstrated that post treatment mastalgia is not a sign or risk factor for recurrent breast cancer. Since there is no evidence of increased risk for recurrent cancer, additional imaging can be avoided and prevent low-value care and instead preserve healthcare resources. Unnecessary breast imaging may also reinforce fearful behavior and exacerbate the belief in patients that “something should always be done (Kool, et al. 2020).” In addition, avoidance of unnecessary imaging can lessen anticipatory anxiety, thereby lowering the likelihood of persistent pain (Lumley, et al. 2011). Reassurance is critical to the management of breast pain, not the unnecessary use of healthcare resources.