Cancer is different for men and women? Exploring the gender preference of cancer

I heard that cancer favors boys over girls?!

This is not groundless. According to the publication of the authoritative journal of the American Cancer Society, among the cancer sites that both men and women may suffer from, except for thyroid cancer and gallbladder cancer, the risk of cancer in most sites is higher in men than in women, especially bladder cancer, stomach cancer, laryngeal cancer and esophageal cancer. The 2022 China Cancer Report revealed that non-reproductive system cancers are more common in men, and their mortality rate is nearly twice that of women.

Overall, cancer seems to favor men more. However, except for lung cancer and digestive tract cancer, which are common in both men and women, some cancers favor men over women, while others favor women over men!

Why is cancer different for men and women? What role does gender play in the development and treatment of cancer? Let’s talk about it today. Let’s get on board!

The three major cancers of "male-focused"

According to data from the National Cancer Center, in 2016, the number of new cancer cases among Chinese men reached 2.48 million, accounting for 54% of the total. Among them, lung cancer, stomach cancer, colorectal cancer and liver cancer ranked at the top of the list. In the same year, the top ten new cancer cases among Chinese men were: lung cancer (540,000 cases), stomach cancer (330,000 cases), colorectal cancer (320,000 cases), liver cancer (300,000 cases), esophageal cancer (220,000 cases), prostate cancer (120,000 cases), pancreatic cancer (70,000 cases), bladder cancer (70,000 cases), thyroid cancer (50,000 cases) and non-Hodgkin's lymphoma (50,000 cases). These ten types of cancer together accounted for 84% of new cancer cases among men.

Among these cancers, prostate cancer, pancreatic cancer and bladder cancer are particularly "favored" by men.

Prostate cancer : As a cancer that only affects men, it has become the second most common cancer type among men worldwide, posing a major threat to the health of middle-aged and elderly men. Since prostate cancer has almost no symptoms in the early stages, once discomfort occurs, it is often in the late stages, so it is called the "silent assassin", highlighting the importance of early screening.

Pancreatic cancer : Known as the "king of cancers", about three-quarters of patients die within one year of diagnosis, and the five-year survival rate is less than 5%. The early symptoms of pancreatic cancer are varied and atypical, and are easily confused with upper gastrointestinal diseases. In outpatient clinics, it is often misdiagnosed as a stomach disease, so its onset is extremely hidden.

Bladder cancer : It is the most common malignant tumor in the urinary system, mainly affecting people aged 50 to 70, and the incidence rate in men is three to four times that in women. The high incidence rate of bladder cancer in men is mainly related to the level of male hormones. At the same time, chronic obstructive factors such as urinary retention, as well as chronic inflammatory stimulation caused by prostatic hyperplasia and bladder stones are also important factors that increase the risk of bladder cancer.

The three major cancers of "heavy girls"

According to statistics from the National Cancer Center, in 2016, the number of new cancer cases in Chinese women reached 2.09 million, accounting for 46% of the total number of cases, among which the number of patients with breast cancer, lung cancer and colorectal cancer ranked at the top. In the same year, the top ten types of cancer in the new cancer cases in Chinese women were: breast cancer (420,000 cases), lung cancer (280,000 cases), colorectal cancer (240,000 cases), thyroid cancer (170,000 cases), gastric cancer (150,000 cases), cervical cancer (110,000 cases), liver cancer (110,000 cases), esophageal cancer (100,000 cases), endometrial cancer (80,000 cases) and ovarian cancer (60,000 cases). These ten cancers accounted for 81% of the new cancer cases in women.

Among these cancer types, breast cancer, thyroid cancer, and cervical cancer have a higher predilection for women.

Breast cancer : As a cancer that is 100 times more likely to occur in women than in men, it is one of the most common malignant tumors in women and is considered the primary threat to women's health. In 2020, the number of new cases of breast cancer in women reached 2.26 million, surpassing lung cancer for the first time to become the cancer with the highest incidence rate worldwide, accounting for about 11.7% of all new cancer cases. Breast cancer usually lacks typical symptoms and signs in the early stages, so it is difficult to attract attention and is usually discovered through physical examinations or special breast cancer screening.

Thyroid cancer : It has become the second most common cancer after breast cancer among women aged 15 to 44 in China.

Cervical cancer : According to statistics, about 135,000 women are diagnosed with cervical cancer in China every year, and 80,000 of them die from it. Cervical cancer has become the fourth largest threat to women's health worldwide, and in China, it is one of the main killers of women's health and life. It is worth noting that 99% of cervical cancer cases are caused by persistent infection with high-risk human papillomavirus (HPV), and the probability of women who have sexual intercourse to be infected with HPV in their lifetime is as high as 60% to 80%. Therefore, for women, HPV vaccination is an effective way to prevent cervical cancer.

These three reasons may be

1. Chromosomes and cancer

Cancer is a disease caused by abnormal cell growth, and sex plays an important role in the risk of non-reproductive cancer. This is mainly related to the genes on the chromosomes that are different for men and women - the X chromosome and the Y chromosome. Simply put, women usually have two X chromosomes, while men have one X and one Y chromosome. These chromosomes carry genes that affect many aspects of our bodies, such as some genes that may affect the risk of cancer. Certain genes on the X chromosome or Y chromosome play a protective role for women or men respectively, and their changes or loss may increase the risk of cancer. Mutations in non-sex chromosome genes (autosomal genes) are also closely related to cancer development and treatment effects, and differences in gene expression between different sexes may be one of the reasons for these differences. By understanding the role of these genes, scientists can better study cancer and develop prevention and treatment methods for different sexes.

2. Metabolism, obesity and cancer

There are significant differences between men and women in many metabolic processes, especially in glucose and lipid metabolism. For example, elevated fasting blood glucose in men is associated with an increased risk of liver and colon cancer. The effects of obesity and related inflammatory responses also differ between the sexes. For example, obesity is more strongly associated with certain cancers in men, such as colorectal cancer, non-Hodgkin's lymphoma, and blood cancers. Therefore, the sex-related metabolic differences that occur during cancer development are very important and may require different personalized treatment strategies for male and female patients.

3. Cancer Immunity

The interaction between the immune system and cancer is an emerging area of ​​research. In general, adult women have more robust immune responses than men, and they are better at generating acute inflammatory immune responses that are beneficial in fighting cancer. This is mainly due to the ability of estrogen to stimulate the production of acute inflammatory cytokines. Women are more effective than men in eliminating infections, which helps to combat the risk of cancer caused by chronic inflammation. The immune defenses of both men and women decline with age, but this decline differs between the sexes. For example, older men have more significant decreases in the number of T cells and B cells than women, which may affect their immune defenses against cancer.

Treatment of moderate to severe gender factors

In the field of immunotherapy, there are significant differences in the response of patients of different genders to immune checkpoint inhibitors. For example, in the treatment of non-small cell lung cancer, female patients have better survival and response rates with anti-PD-1 or anti-PD-L1 treatment than male patients. However, in the treatment of other types of cancer, such as colorectal cancer and skin melanoma, male patients may get better treatment results.

Gender differences in radiotherapy and chemotherapy are also very obvious. Studies have shown that women with esophageal squamous cell carcinoma have significantly better survival after radiotherapy than men, but women are also more likely to experience cardiac toxicity. In children with cranial radiotherapy, girls' IQs are more severely impaired. Women tend to have stronger toxic reactions to chemotherapy, which may lead to them receiving relatively lower doses of chemotherapy. This difference may be due to gender differences in drug metabolism and excretion.

In the new precision cancer medicine, more than half of the genes have been identified as potential therapeutic targets or biomarkers. Future strategies for developing new anticancer drugs should take into account gender differences, such as the speed of drug metabolism, drug excretion rate, body composition, and physiological differences, to maximize the therapeutic effect.

In short, the occurrence of cancer is closely related to gender, and this connection stems from the combined effects of genes, epigenetics, and sex hormones. Genetic damage occurs earlier in men, so it is recommended to screen young people for cancer earlier. Adjusting treatment plans for different genders can achieve more personalized and precise treatment.