Every year, about 10 million people worldwide die from cancer (1). Cancer affects not only the length of life but also its quality (2). Globally, cancer has become an expanding health, economic, and social burden (3). The most recent report from the Polish Cancer Registry, published in 2023, indicates that approximately 1.17 million individuals in Poland have currently diagnosis of cancer, and around 100,000 patients die from cancer each year (4). Cancer is the second leading cause of mortality in Poland, after cardiovascular disorders, accounting for 25% of all deaths (5).

Public awareness of potential causes of cancer, screening tests and other activities that can reduce the risk of disease is insufficient (6). Lack of knowledge induces cancer-promoting behavior and an inability to avoid risk factors, whereas 44% of cancer deaths are due to modifiable variables (7), which are common in all developed countries (8). Modifiable factors are, for instance, tobacco smoking, obesity and diet (processed meat and lack of fiber), infections, sun exposure, alcohol drinking, and hormonal contraception (9). Recent studies show that Polish citizens have a lower tendency to attend cancer screenings than other European countries (1). It has been proven that Polish women present a low level of recognition of both the risk factors and importance of screening for namely breast cancer (10).

Early prevention has a chance of reducing the possibility of cancer in the future (11). Therefore, knowledge about cancer should be available not only to older people, among whom cancer is most common, but especially to young people to allow them to induce changes in their lifestyle or obtain an early diagnosis to decrease cancer morbidity and mortality rates in Poland and worldwide. Students’ education on the subject is extremely important, as young adults typically begin engaging in unhealthy habits, such as alcohol consumption or smoking, during their college years (12).

The significance of modifiable risk factors was outlined as early as 1974 in the “New Perspective” report, which introduces the concept of “health field” according to which four interdependent determinants constitute a base for properly functioning healthcare systems among which lifestyle accounts for 50% (13). The World Health Organization states that between 30% and 50% cancer deaths could be prevented by lifestyle modifications or avoidance of principal cancer contributors with an additional implementation of existing evidence-based prevention strategies (14). Based on that, the shift of the focus point from tertiary care to primary prevention appears to be more beneficial, as a large percentage of cancer types could be prevented instead of treated.

The results of previous studies conducted on students showed a lack of sufficient knowledge about cancer and suggested the need for appropriate education (15–17). Young people not only do present inadequate knowledge of cancer causative factors but also tend to believe in discredited information.

Objective of the study was to assess beliefs related to the causes of cancer among medical and non-medical students enrolled in various university courses around the world.

Most of the students in current study knew that cancers can have a genetic basis and that a family history of cancer increases the risk of developing cancer. Students most often named properly smoking, drinking alcohol, sunbathing/using tanning beds, exposure to ionizing radiation, diet, and exposure to harmful occupational agents as cancer risk factors. However, only less than half of the students pointed to other important factors, such as lack of physical activity, viral or bacterial infections, hormonal factors, and drinking hot beverages.

In fact, the causes of cancer are complex. There are known hereditary cancers and those that develop due to external factors. Many cancers depend on smoking, alcohol consumption, diet, physical activity, exposure to harmful factors such as sunlight, ionizing radiation, and occupational and infectious factors. Young people’s knowledge of the main causes of cancer is key to future reductions in cancer incidence and mortality in the population. Bad lifestyle habits such as smoking, drinking alcohol, using tanning bed, poor physical activity, and unhealthy eating habits have just been reported frequently among adolescents (18–22).

Cigarette smoking as a cancer-causing factor was mentioned by almost all students (95% of Polish and 85% of foreign students). Similarly, in the US in the study of adolescents’ perceptions of cancer risk factors among middle and high school students, 91% of participants recognized smoking as a behaviors affecting cancer risk factor (22). But among the “three major cancer factors,” 70% of Polish students and only 56% of foreign students indicated smoking cigarettes. In fact, smoking causes over 90% of lung cancer and up to 30% of all cancers in the developed countries (23, 24). In the previous study among Polish high school students aged 17–18 years, as a major cause of cancer, only 18.5% of students indicated smoking (25). However, in some studies, both adults and adolescence indicated smoking at the top of cancer risk factor (26–29).

The most of Polish students (91%) and foreign students (86%) pointed genetic factors as a cancer risk factor and they included it into the “three major cancer factors” (81% of Polish and 75% of foreign students). Study among even younger high school students reported that most of them perceived the genetic factors as the most important factors affecting cancer development (25). The study conducted by Karadeniz et al. (29) reported that 83% of adults indicated family history of cancer as a main risk factor for cancer.

In England, more than half of adults surveyed associated alcohol with cancer (30). Unfortunately, young Polish high school students from our previous work completely failed to see the link between drinking alcohol and cancer (25). Drinking of alcohol was recognized as a cancer risk factor by nearly 80% of Polish and foreign students in current study. Participants who reported that their relatives or friends had been diagnosed with cancer were significantly more likely to cite drinking alcohol as a risk factor for cancer. Similarly Lykins et al. (31) showed that, if there was cancer in family, then people significantly often pointed alcohol.

A significant difference was found in the responses of Polish and foreign students regarding whether diet plays a role in cancer development. There were a higher number of foreign students that believed so, compared to Polish students (94% vs. 60%). In the US, 80% of adolescents’ perceptions recognized poor diet as a cancer risk factor (22). It should be mentioned that Polish cuisine is rich in fats, especially saturated and refined carbohydrates, which can increase the risk of obesity (32). Especially since in 2022, Poland had the second highest prevalence of obesity in men among European countries (33). The study by Boylan et al. (34) showed that Polish people revealed a limited knowledge about healthy eating. Traditional Polish cuisine is still used because of the culture and conservative customs celebrated through food. Factors that were overlooked by respondents are infections. Viral infections were pointed by only 30% of students and bacterial infection by only 20% of students. Actually, approximately 13% of worldwide cancer diagnoses were associated with carcinogenic infections, mostly Helicobacter pylori, human papillomavirus (HPV), hepatitis B and C virus, and Epstein–Barr virus (14). In some countries (Belgium, Spain, UK), 85%–90% of students link HPV infection to cervical cancer, whereas only 20%–50% of students in others (Nigeria, Costa Rica, Scotland, and Turkey) (35–39). The discrepancy between different countries may be related to cultural attitudes toward health, the global population’s knowledge of cancer, encouragement of cancer screening, and the organization of health care. Eighty-five percent of all investigated students believe that cancer can be prevented. On the other hand, 41% of Polish students and as many as 79% of other students consider cancer to be an inherited disease and thus one that cannot be prevented. Our previous study showed that 81% of high school students claimed that people can modify their own cancer risk (35). In the US, 66% of adolescence indicated that individuals have control over their risk of cancer (22). Two-thirds of older adults (65 years and older) in Poland believed that cancer depends on their lifestyle and environment (40). Factors contributing to an elevated cancer risk can be categorized into intrinsic elements, which are unmodifiable, such as random mutations during DNA replication, and non-intrinsic factors, which can be divided into endogenous and exogenous categories. Endogenous factors are partially modifiable and include aspects like biological aging, genetic predisposition, and hormonal imbalances, whereas exogenous factors are fully modifiable and encompass elements such as radiation exposure, viral infections, unhealthy lifestyle choices, and occupational risks, which all could be avoided (41). It is crucial to recognize that students lack sufficient awareness regarding effective cancer precautionary measures and their application (42–44). Despite the correlation of students’ beliefs with risk factors and their influence on the development of the disease, they overestimated the importance of genetic predisposition.

By categorizing the student cohort from Poland and other countries into medical and non-medical, notable distinctions were identified in recognition of cigarette smoking, genetic factors (cancers in the family), sunbathing/using tanning beds, exposure to ionizing radiation, exposure to harmful occupational factors, and diet in favor of Polish medical students. Opposite foreign medical students more often indicated viral infections and hormonal contraception as important cancer factors in compare with non-medical students. However, viral and bacterial infections and lack of physical activity were relatively rare indicated by medical students—both Polish and foreign. This is in line with the results of other studies with research indicating that medical students do not have enough knowledge about cancer risk factors, despite their education (15, 42–45).

It is interesting that 18% of foreign students and 11% of Polish students indicated answer “cancer is a matter of chance.” Fatalistic beliefs about cancer that “if it is meant to be, it will be” and “lack of luck” showed about 10% both Polish and foreign students. In another study on Polish people but older (65 years and over), only 3% claimed that what “will happen will happen” (40). However, 24% of respondents considered that “if in family someone has a cancer, I will certainly get sick as well” (40). The fatalistic beliefs could effect on avoiding visits to physicians and participation in cancer screening.

Students were able to correctly indicate the main cancer risk factors, such as smoking, drinking alcohol, UV radiation, and diet. They overestimated the importance of genetic factors while not recognizing some of the important modifiable factors, such as lack of physical activity or viral infections. Furthermore, Polish students were less knowledgeable on nutrition than students from other countries. Medical students had a better understanding of cancer risk factors in comparison with non-medical students.