The increasing financial relationships between pharmaceutical companies and breast cancer specialists in Japan, as highlighted in this study, represent a significant trend in the pharmaceutical payments coming into the breast cancer care in Japan. The overall rise in payments, with a notable average annual growth of 10.1%, reflects the pharmaceutical industry's strategic efforts to engage healthcare professionals more deeply, as there has been a downward trend in HCP contact in the pharmaceutical industry in recent years, with HCPs becoming more selective in their interactions with pharmaceutical companies.36
This increase is particularly pronounced in companies such as Pfizer Inc. and Eli Lily Japan K.K's, which have expanded their payment allocations substantially. Specifically, Pfizer's payments surged following the September 2017 introduction of Ibrance (palbociclib),37 and Eli Lilly's payments increased significantly after introducing Verzenio (abemaciclib) in November 2018.38 These increments, captured in the total payment growth from USD 2,857,414 in 2016 to USD 3,798,523 in 2019, underscore the competitive dynamics within the oncology sector, particularly in the domain of CDK4/6 inhibitors. Despite the similar therapeutic applications of these drugs to existing treatments,39 their aggressive promotion can be attributed to the marginal but clinically significant benefits they offer over competitors, a factor crucial in a highly competitive oncology market.40,41
On the other hand, in the context of Chugai Pharmaceutical's financial engagements, their consistent high payments can largely be attributed to their portfolio of established therapies, particularly for HER2-targeting drugs such as Herceptin (trastuzumab), Perjeta (pertuzumab), and Kadcyla (trastuzumab emtansine), as well as Avastin (bevacizumab) for HER2-negative cases. This may be the primary reason why a launch of Tecentriq (atezolizumab) did not increase the payments in 2019.42 However, the evolving competitive landscape, with new entrants like Enhertu manufactured by Daiichi Sankyo, will pose a potential challenge to established players like Chugai Pharmaceutical. Enhertu has been approved not only for HER2-enriched breast cancer but also for low-HER2 breast cancer, positioning it as a competitor in both segments.43,44 Thus, there is a possibility that Chugai Pharmaceutical would increase its payments to the HCPs to protect its sales and share against Daiichi Sankyo. Similarly, Pfizer's BRCA-targeted agent talazoparib, which has been approved in Japan in January 2024, does not have a clear advantage over AstraZeneca's Lynparza and may prompt increased investments by AstraZeneca.45
The already escalating and likely to further increase payments in the pharmaceutical sector are contributing to further complexities in market dynamics. This trend underscores the need for a comprehensive analysis of promotional strategies and their implications for treatment decisions and guideline recommendations. Intriguingly, the most recent 2022 guidelines continue to endorse drugs such as Tecentriq and Avastin despite their withdrawal from the market in the United States.46 Furthermore, this study revealed a concerning trend in the field of breast surgery, akin to or potentially more pronounced than in other areas such as dermatology and respiratory medicine,34,35 where payments are disproportionately concentrated among a select group of specialists. This skewed distribution raises the possibility that the recommendations in clinical guidelines might be influenced by authors who maintain robust relationships with pharmaceutical companies, thereby potentially affecting the objectivity of guideline recommendations.
Of note, pharmaceutical companies' promotional strategies heavily favor lecture-based engagements. This method enables the wide dissemination of information through a singular, concerted effort, providing a pragmatic approach for the involved companies. Indeed, such approaches have become vital for interaction and information acquisition among regional healthcare providers. However, reliance on these strategies raises substantial concerns regarding their broader impact on the medical community.
Furthermore, an important point to consider is the potential contribution of these strategies to the male-dominated nature of breast surgery. Specifically, given that over 90% of surgeons in Japan are male, yet the female proportion in breast surgery approximates 40%, the conventional scheduling of post-clinical evening lectures significantly hinders the participation of female physicians.47 This scheduling conflict, juxtaposed with the dual demands of professional obligations and familial roles, often precludes Japanese women doctors from attending such events, thereby exacerbating gender disparities within the medical community. It is essential to explore more inclusive and accessible approaches to organizing educational events, ensuring equitable participation across genders and accommodating the diverse needs of the medical community.
This study has several limitations. First, the payment data was manually collected from 93 pharmaceutical companies, which introduces the possibility of errors in data gathering and reporting. Second, our focus was on direct payments for lecturing, writing, and consulting, excluding indirect financial relationships like meals, travel, and research grants, potentially underrepresenting the total financial engagements. Additionally, the study used the most current list of breast cancer specialists without historical data for previous years, which might affect the accuracy of trend analyses. Also, the lack of detailed information on the purpose of payments and the specific drugs involved limits the depth of our analysis. Finally, the absence of a strict monitoring system for the accuracy of disclosed payments by pharmaceutical companies may question the reliability of the data, given the lack of penalties for non-disclosure under JPMA guidelines.