According to the GLOBOCAN 2020 report, breast cancer took first place among the cancer-related deaths in women in 110 of 185 countries (Amato et al. 2023; Mubarik et al. 2023), and overall gynaecological cancers remain over 14% of cancers diagnosed among women worldwide. Cervical, uterine, and ovarian cancer constitute respectively 6.5%, 4.5%, and 3.4% of worldwide cancer incidence in women (Gil-Ibanez et al. 2023a). Cancer therapy, including surgical, chemo- and radiotherapy, affects the physical and mental health of patients, significantly reducing their quality of life (Gil-Ibanez et al. 2023a, b; Keyvani et al. 2023). This makes gynaecological cancer a serious global public health problem requiring appropriate solutions.

Poland is one of the countries in Central Europe that underwent political and economic transformation at the end of the1980 s/start of the 1990s. The structural changes also affected the healthcare system, and in 2003 the National Health Fund of Poland (NFZ) was established as a single entity financing healthcare services from public funds. Simultaneously, the share of private health insurance was negligible, so the nationwide pre-processed NFZ data shared after the settling-in of the healthcare services may be considered the most reliable and complete.

In our study, we have analysed data concerning 272,550 women diagnosed in Poland in the period 2015–2021 with breast cancer (n = 154,069), cervical cancer (n = 26,273), uterine cancer (n = 54,688), and ovarian cancer (n = 37,520).

Breast cancer was the most frequent cancer diagnosed among females in Poland in 2015–2021 and its incidence was characterized by a clear spatial nationwide diversity along the north-west/south-east axis. Although the risk factors for breast cancer are diverse and include obesity and lifestyle as well as procreative and genetic factors (Qian et al. 2023), the increased incidence of breast cancer noted in the western areas of Poland in 2015 was most probably affected by the increase in mammographic screenings performed in the national screening program (Fig. 2). The epidemic situation remained stable in the period 2015–2019, unaffected by the COVID-19 pandemic but in 2020 a significant decrease of the incidence (over 10%) was noted that can be related to the involvement of healthcare resources in the fight against the pandemic. Subsequently, in 2021 a disproportionate increase in breast cancer incidence was observed. It may be assumed that females whose cancer diagnosis was delayed due to the COVID-19 pandemic will have a more advanced stage of cancer, which is associated with a worse prognosis. Our findings correspond with the US Medicare system data indicating screening reduction from 40%−60% to 6%−17% in the second quarter of 2020. A similar situation also occurred in some European countries, multiplied by special inequalities, e.g. in Italy, while in others (such as the Netherlands or France) the changes were slighter. Nevertheless, epidemiological models predict an increased mortality among breast cancer patients because of COVID-19-related limited access to healthcare services (Amato et al. 2023).

The importance of prevention and diagnosis of breast cancer at an early stage in lessening the effects of cancer therapy is well established (Reyna-Sevilla et al. 2023). Unfortunately, in the period 2015–202,1 the city of Wrocław was the only subregion in which the implementation of the breast cancer screening program increased. The increase in the number of screenings performed resulted in an increase in the annual percent change in breast cancer incidence. The opposite situation was observed in the Biała Podlaska subregion where both the greatest reduction of the incidence’s annual percent change and limitation in the implementation of the screening program occurred. These two contrasting cases well describe the relationship between performing screening tests and the diagnosis of diseases. It is important in breast cancer because, as shown in data from Denmark, women not participating in preventive programs have a more than 6-times greater risk of being diagnosed with breast cancer at an advanced stage (Amato et al. 2023). The findings by Qian et al. show that the low percentage of breast cancer cases diagnosed in China at early stages is a consequence of the lack of screening programs (Qian et al. 2023).

Our results also show the relationship between the availability of gynaecologists and breast cancer incidence in subsequent years, but there was no correlation between cancer incidence and the ratio of nurses and midwives. This suggests that physical examination is an important factor in breast cancer diagnosis, as well as the use of mammography as the standard procedure.

Despite the availability of both primary and secondary preventions, cervical cancer still has an important incidence for an underscreened population (Gil-Ibanez et al. 2023a). Because of the usage of the Papanicolau smear in routine gynecological procedure, both incidence and mortality of cervical cancer have decreased in most developed countries since the 1950s (Zreik et al. 2023; Zhang et al. 2020). Moreover, the infection of human papillomavirus (HPV) is a well-established risk factor of cervical cancer (zur Hausen 1989, Walboomers et al. 1999, Wang et al. 2017, Cohen et al. 2019), and the development of HPV vaccines limits of its incidence (Reyna-Sevilla et al. 2023). Nevertheless, cervical cancer remains one of the most common cancers as well as the most frequent cause of death among women worldwide (Zhang et al. 2020, Akbari et al. 2023, Karcheva et al. 2020).

As with breast cancer, a noticeable decrease in cervical cancer incidence in 2020 compared to 2019 by over 15% was found, and subsequently, the incidence has increased. That may be directly related to the limited availability of inpatient healthcare services due to pandemic restrictions. Overall in the period 2015–2021, a clear decrease in cervical cancer incidence was noted in almost all Polish subregions, except for Chełm & Zamość, Tarnów, and the city of Szczecin. However, this result should not be interpreted positively because of the limitation in the execution of the national cervical cancer screening program execution to about 10%–20% of the qualified population on January 1 st 2016 (Fig. 3). Such results are far below expectation because in developed countries the effectiveness of cervical cancer screening programs reaches about 80%–90% (Zhang et al. 2020). Our findings might correspond with the results of Akbari et al., who pointed out that low incidence rates of cervical cancer noted in Iran were affected by cultural factors and the insufficient availability of screening (Akbari et al. 2023).

Despite the incidence of cervical cancer noted in Poland is lower compared to most countries of the former socialist bloc (such as Lithuania, Estonia, Romania, Bulgaria, Latvia, Hungary, and Slovakia), it remains higher compared to the countries of Western Europe and Scandinavia (France, UK, Austria, Italy, Luxemburg, Netherlands, Switzerland, Finland, and Iceland) (Karcheva et al. 2020). Unfortunately, the 5-years survival rate among cervical cancer patients in Poland is one of the lowest in Europe (Bielska-Lasota et al. 2007), which requires urgent public health intervention.

Similarly, uterine cancer incidence and mortality have increased over the past 2 decades, becoming an important issue for women’s health (Whetstone et al. 2022). Unlike cervical cancer, uterine cancer is diagnosed mainly in highly developed countries, and its incidence is highest in North America and the countries of Eastern Europe (Jiang et al. 2023). Our results, indicating a reduction in uterine cancer morbidity both in the period 2015–2019 (unaffected by the COVID-19 pandemic) and overall in the period 2015–2021 are different from the Wijayabahu et al. findings indicating a steady increase of the incidence in uterine cancer (Wijayabahu et al. 2024). Additionally, because uterine cancer occurs more frequently among postmenopausal women, an increase in the incidence could be expected due to the aging of the Polish society. There was also no relationship between uterine cancer incidence and the availability of medical professionals. This issue requires further in-depth analysis.

Ovarian cancer is difficult to diagnose in the early stages, so in most patients, it is detected at an advanced stage, as a result of which this cancer is characterized by a high mortality. The low 5-year survival rate makes it one of the most important problems for gynaecologic oncology (Gil-Ibanez et al. 2023a, Keyvani et al. 2023, Zamwar and Anjankar 2022). The exact ethology of the disease is not clearly understood, but the lifestyle factors of smoking, obesity, and an unhealthy diet may increase the risk of the disease. Genetic factors and family history are important as well (Mazidimoradi et al. 2022; Ali, et al. 2023). According to WHO data, ovarian cancer is diagnosed more frequently in North America (8.42 per 100,000) and the high-developed countries of Europe (10.29 per 100,000). The Global Burden of Disease report shows that the highest incidence rate was noted in Central Europe (11.73 per 100,000). Simultaneously, the standardized death rate of ovarian cancer noted in Poland is one of the highest (Mazidimoradi et al. 2022).

Our results show an increase of the incidence of ovarian cancer in a number of Polish subregions such as Cracow (rural), part of the Silesian province (subregions of Bytom, Gliwice, Katowice, Rybnik, and Tychy), the city of Łódź and some eastern areas. The Cracow and Silesian voivodeships are wealthy areas with good availability of healthcare resources. The urban environment mixed with lifestyle changes may affect the increase of the ovarian cancer burden that the available data suggest (Mazidimoradi et al. 2022, Ali et al. 2023, Wichmann and Cuello 2021). The results concerning the relationship between healthcare professionals and ovarian cancer morbidity remain inconclusive. Nevertheless, both in gynaecologists and nurses and midwives a significant correlation was noted in the years 2020 and 2021 affected by the pandemic. Ovarian cancer is diagnosed mainly by a physical examination and transvaginal USG. During the pandemic, in areas with better availability of medical staff, patients could have had better access to gynaecological services, but further investigation is required to confirm this.

For each of the analysed cancers, a clear decrease of incidence rates was noted in 2020. This was most probably affected by the involvement of the healthcare system in fighting the COVID-19 pandemic. The consequence of this was the limitation of accessibility and availability of healthcare services for non-COVID diseases. Moreover, many non-urgent medical consultations were delayed because of care and support by medical professionals and patients’ and physicians’ fear of COVID-19 infection, especially before vaccine development.