Uncovering the causes of cervical cancer

Cervical cancer occurs all over the world and is one of the most common cancers in the human body. It not only ranks first among cancers of the female reproductive organs, but is also the most common cancer among various malignant tumors in women. Let us learn about this knowledge together.

【Etiology】

The cause of cervical cancer is still unclear, but a large amount of data from home and abroad confirms that it is related to the following factors:

(1) Exogenous factors

The incidence of cervical cancer among Jews is low. Research suggests that the reason may be related to the Jewish custom of removing the foreskin of male babies after birth. However, some believe that among Jewish women who have not removed the foreskin, cervical cancer is also rare. There is currently a lack of experimental data to prove that circumcision can reduce the incidence of cervical cancer, although Nahmos has isolated HSV-2 from the smegma of men.

Singer (1976) and others proposed that histones and protamines contained in the sperm head are carcinogenic factors that can act on the DNA filaments of cervical metaplastic cells. Coppelson and Reid and others believed that adult women, especially during pregnancy, have active squamous cervical epithelium that is most susceptible to malignant transformation, which may be related to DNA viruses. Of course, sperm itself can also have a mutagenic effect on the cervix under special circumstances. These new hypotheses need to be further confirmed.

(2) Relationship with sexual life, marriage, and pregnancy

Women who have sex too early (before the age of 18) have a 4-fold higher incidence of cervical cancer than those who start sex after the age of 18. If women start sex early and have sexually transmitted diseases such as syphilis and gonorrhea, their incidence of cervical cancer will be 6 times higher than normal women. It has been confirmed that if women have sex with multiple men, they are more likely to develop cervical cancer. This may be because the lower reproductive tract of prepubescent women is not yet mature and is more sensitive to the stimulation of carcinogenic factors. If they start sex early, they are more likely to develop cancer once they are infected by certain bacteria or viruses.

(3) Sexually transmitted diseases

Before the 1960s, it was believed that the incidence of cervical cancer was high in patients with syphilis, but direct evidence that syphilis causes cervical cancer has not yet been found. Trichomonas vaginitis often coexists with cervical precancerous lesions or cervical cancer. Parfen et al. found that patients with atypical cervical hyperplasia and Trichomonas vaginitis have an increased chance of transformation into invasive cancer, and have successfully infected animals with Trichomonas to induce cervical cancer. However, both are sexually transmitted diseases and can coexist, and the vaginal pH of patients with atypical cervical hyperplasia is often alkaline, which is conducive to the growth of Trichomonas, so it cannot be confirmed that Trichomonas infection can induce cervical cancer.

(4) Endocrine factors

Whether sex hormones promote the occurrence of cervical cancer has also been a topic of research for many years. Animal experiments have successfully used estrogen to induce squamous cell carcinoma in mice, but there is no conclusive evidence that exogenous estrogen can induce cervical cancer in humans.

(5) Viral infection There are many types of viruses that can cause infection in the female lower reproductive tract. The relationship between viral infection and cervical cancer has been studied for decades. So far, it is believed that three types of viruses may be related to the occurrence of cervical cancer: herpes simplex virus type 2 (HSV-2); human papilloma virus (HPV); human cytomegalovirus (HCMV).

(6) Fungal infection and other factors

Clinically, it has been observed that cervicitis is closely related to the occurrence of cervical cancer. Cervical erosion is an important risk factor because cervical cancer most often occurs in multiparous women, mostly in the eroded area and torn part of the cervix. Fungi are one of the predisposing factors of cervicitis and cervical erosion. In addition to being carcinogenic, they can also produce carcinogenic toxins and synthesize carcinogenic nitrite with secondary amines and nitrites.

【Pathological changes】

Cervical cancer is mainly squamous cell carcinoma, accounting for about 90% to 95%, and adenocarcinoma accounts for only 5% to 10%. However, there is no special difference in appearance between the two types of cancer, and both occur in the cervical vagina or endocervical canal.

(I) Before developing into invasive cancer, there is no special abnormality in naked eye observation, or it is similar to common cervical erosion. With the appearance of invasive cancer, the cervix can show the following four types:

1. Exophytic type: also known as hyperplastic or cauliflower type. It develops into cauliflower-like growths of varying sizes that protrude into the vagina. They are fragile and prone to bleeding.

2. Erosive type: There are rough granular erosion areas around the surface of the external cervical os, or irregular ulceration surfaces that bleed easily when touched.

3. Ulcerative type: Regardless of the exogenous or endogenous type, after further development, the cancerous tissue necrose and sloughed off, forming an ulcer, and even the entire cervix is ​​replaced by a large cavity. Because of frequent secondary infection, there is a foul-smelling secretion. Cervical cancer, especially adenocarcinoma, can also grow into the endocervical canal, making the cervix barrel-shaped and enlarged, which is also a type of endogenous type.

4. Endogenous type: also known as infiltrative type. Cancerous tissue infiltrates deep cervical tissues, and the cervix becomes enlarged and hard, but the surface is still smooth or only superficial ulcers.

The above is some knowledge about cervical cancer that we have prepared for you today. I hope it can be helpful to you. If you have any other needs, you can also consult our online consulting experts of Feihua Health Network. We are always here to answer your questions. Feihua Health Network has always been by your side and cared about your health issues! Feihua Health Network wishes you good health!

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