As far as we know, this is the first Japanese study to investigate resignation rate and SL rate in breast cancer patients by national research project of the MHLW, excluding Saito’s cross-sectional study (n = 105), which investigated work-related factors opposed to clinical factors (e.g., cancer stage, surgery) [18]. This study revealed that 14.9% of Japanese female breast cancer survivors quit their jobs after being diagnosed with cancer, while the post-cancer diagnosis resignation rate differed significantly according to educational level, cancer stage, and occupational type. As Boer’s systematic review reported that CSs were more likely to be unemployed compared to healthy controls (33.8% vs. 15.2%; pooled relative risk: 1.37) [19], it is important that developed countries support CSs to avoid potentially high numbers of resignations [20]. The resignation rate (14.9%) of BCSs in this study was lower than the resignation rate. Endo et al. reported that resignation rates (12.4%) among total CSs in Japanese were low because it is extremely difficult and uncommon for employers to fire employees in Japan [20, 21]. The Labor Contract Act states, “A dismissal shall, if it lacks objectively reasonable grounds and is not considered to be appropriate in general societal terms, be treated as an abuse of right and be invalid” [20].
This study showed that predictors for resignation after breast cancer diagnosis were age at diagnosis, lower levels of educational attainment, use of SL; predictors of taking SL were limited to having undergone surgical intervention. We speculated that highly educated or sick leaved CSs might be confounded by being able to easily access the SL scheme for workers at larger companies.
Regarding predictors of resignation after breast cancer diagnosis, the present study demonstrates that younger BCSs resigned more frequently than those in the older age group, in accordance with previous studies [22, 23]. These previous studies argued that young BCSs had a higher risk of losing paid employment because breast cancer treatment is often more aggressive in younger patients and young BCSs may therefore also experience more severe long-term adverse effects, including work-related effects. However, Fantoni et al. reported that older age was associated with difficulty continuing work and a higher risk of unemployment [20]. Our data may suggest that older people may be more reticent to resign their jobs, given typical age-associated difficulties in finding new employment. Older people may have more knowledge and technology compared to younger people [20,22).Further studies exploring the reasons behind resignation are warranted.
Secondly, patients with a lower educational attainment were at higher risk for resignation compared with those with higher educational attainment. Our findings are consistent with previous studies in non-Asian populations [12, 24-28]. However, comparison of resignation rates with other countries studies warrants careful consideration, given important differences in socioenvironmental factors, including widely differing national systems regulating provision of medical leave, as well as availability of company-based healthcare resources [29]. In addition, income correlates with levels of educational attainment, while lower income also associated with increased likelihood of resignation and unemployment among breast cancer patients [12, 25, 30-32]. Furthermore, education attainment is likely related to occupation type, with less educated individuals more likely to be working in physically demanding jobs such as manual labor [33]. A MHLW survey in Japan showed that people with lower levels of education were more likely to work in physically demanding jobs such as hospitality and wholesale and retail trades [34]. Employees in more physically demanding jobs such as manual labor and blue-collar work are more susceptible to resignation [12, 25, 28, 35, 36]. Petersson et al. reported that a higher education level was related to greater dedication to work, while RTW was earlier in patients who valued their work more highly [37, 38].
Thirdly, our study showed that the risk of resignation among BCSs who utilized SL after breast cancer diagnosis was substantially higher than those who did not. These findings are consistent with previous studies showing a correlation between length of SL and RTW, with longer SL making RTW and continued employment more difficult [39, 40]. Conversely, Azarkish et al. reported no relationship between taking SL and job loss [27]. Longer SL is reported to be associated with more invasive treatment, advanced breast cancer, and economic deprivation, all of which are factors related to unemployment [25, 40, 41].
Regarding predictors of SL utilization, our findings showed that BCSs who underwent surgery took SL more frequently than those who underwent non-surgical interventions. The distinction between BCSs who underwent surgery and who do not mean those who have advanced stage or not, because, except for stage IV where distant metastasis is apparent, almost all BCSs experience surgery in general. Previous studies reported that breast cancer surgery was associated with SL lasting 1 month or longer [42, 43], while median duration of hospitalization among BCSs were reported to be about 6.79-10.37 days in Japan [44]. Surgical treatment may result in challenging sequelae including scar pain and reduced range of motion, particularly in the arm and chest region, fatigue, and lymphedema; these symptoms increase the time to RTW and are related to unemployment[44]. Wennman-Larsen et al. reported that arm morbidity shortly after surgery affected 10% of BCSs, and that 60% of those patients were on SL; SL was linked to arm morbidity, axillary clearance, and strenuous work posture [45]. More invasive surgery is related to more advanced breast cancer, which caused longer SL [41]. Petersson et al. proposed that various side effects due to surgery influenced impaired work capacity and lead to longer SL in occupations requiring strenuous work postures [46].
Our study has some limitations that warrant note. First, recall bias is possible given the nature of the self-reported questionnaire tool. In particular, as the cognitive function may be adversely affected by some forms of treatment, some respondents were unable to remember when they were diagnosed with breast cancer, and were unable to report how their work changed after cancer diagnosis. Second, this study was affected by survivorship bias, a form of selection bias, as BCSs who died before completing the questionnaire were not included. We speculate that the resignation rate among BCSs is underestimated due to the death of a breast cancer patients who left their jobs soon after breast cancer, especially in cases of advanced-stage disease. In addition, younger patients may feel more comfortable than older patients given the online delivery and design of the survey.
Finally, our sample size was small, with a large number of respondents ultimately excluded from analysis; large scale further investigation is required to corroborate our results.
Regarding future tasks, a prospective cohort study (such as an RTW intervention study) for working BCSs is needed in Japan to more fully understand the association between the symptoms of BCSs and work-related factors.