宫颈癌的事实
释义
Cervical cancer iscancer of the uterine cervix (the tip of the uterus that extends into the vagina).
描述
浸润性宫颈癌占美国女性所有癌症的2.5%。美国每年诊断出约13500例浸润性宫颈癌，而至少有50000例新的浸润前癌症，即原位癌，癌细胞局限于宫颈表面皮肤。
自1940年以来，宫颈癌的发病率一直在稳步下降，因为大多数没有症状的女性都会接受宫颈和阴道巴氏涂片筛查。白人女性最终患宫颈癌的概率从1975年的1.1%下降到1985年的0.7%.同样，对于黑人女性来说，这种可能性从1975年的2.3%下降到1985年的1.6%.总的来说，死亡率在1992年至1994年间下降了45%，而且由于筛查程序的有效性提高，死亡率一直下降到今天。
超过90%的宫颈癌起源于宫颈的表面细胞，称为鳞状细胞癌。大约5%到9%开始于腺组织，被称为腺癌。腺癌更难诊断，但其治疗方法与鳞状细胞癌相同，各阶段的生存率相似。
There are several types of adenocarcinoma. About 60 percent are the endocervical cell type, 10 percent are each endometrioid and clear cell carcinomas, and 20 percent are adenosquamous carcinoma.
有两种罕见的宫颈癌，称为小细胞癌和宫颈肉瘤。两者的预后都很差。
大多数科学家认为，宫颈疣或浸润前宫颈癌可能会在宫颈感染病毒后数月或数年内发展人乳头瘤病毒(HPV). This early tumor, known as mild dysplasia or cervical intraepithelial neoplasia (CIN-1) or Grade 1, can progress to moderate dysplasia (CIN-2), then to severe dysplasia and carcinoma in situ (CIN-3) and eventually to invasive carcinoma. Most physicians believe that about two-thirds of all cases of severe dysplasia will progress to invasive cancer if left untreated. This transformation takes anywhere from 3 to 30 years; about 10 years on the average.
Once the cervical cancer becomes invasive, it can spread locally to the upper vagina and into the tissues surrounding the upper vagina and the cervix (the parametrium). Eventually, it grows toward the pelvic sidewall, obstructing the tubes (ureters) that drain urine from the kidney to the bladder. It can also spread to the bladder and rectum.
宫颈肿瘤细胞可以侵入淋巴系统并扩散到盆腔壁的淋巴结。最终，它们可能扩散到骨盆较高的髂淋巴结、主动脉淋巴结、锁骨以上的淋巴结，偶尔也会扩散到腹股沟淋巴结。
转移瘤也可以通过血流扩散到外阴道、外阴、肺、肝和脑。盆腔神经侵犯在晚期病例中很常见。当肿瘤完全穿透宫颈时，也可能在腹部扩散。
Causes
一般来说，宫颈癌的主要风险因素似乎包括早年开始性活动、多个性伴侣（或有多个性伴侣的伴侣）、感染人乳头瘤病毒16和吸烟。
超过90%的宫颈癌是鳞状细胞癌，研究人员认为这种癌症可能是一种性传播疾病。有很多证据表明宫颈癌与性传播有机体有关。
Most researches believe that the human papilloma virus (HPV) is a strong cofactor in the development of pre-invasive and invasive carcinomas of the cervix, as well as pre-invasive and invasive squamous cell cancer of the vagina and vulva. Ninety to nintey-five percent of squamous cell carcinomas of the cervix contain the human papilloma virus DNA.
The virus is a sexually transmitted disease. There are more than 50 types of human papilloma virus (HPV) that infect humans. Types 6 and 11 usually cause warts, while types 16, 18, 31 and 33 usually result in high-grade cervical dysplasia (CIN-2 and CIN-3) and carcinomas. The virus infects the tissues of the lower genital tract and may produce obvious genital warts or mild, moderate or severe dysplasia and carcinoma in situ.生殖器疣are associated with cervical, vaginal and vulvar dysplasia and invasive carcinoma (in 25 percent of all cases).
However, although infection with HPV does increase the risk of cervical cancer, many women infected by HPV do not go on to develop cervical cancer. Co-factors such as immune system functioning, nutrition and diet, hormones, smoking and other sexually transmitted diseases (STDs) are currently being evaluated by researchers.
有几个因素可以降低女性患宫颈癌的风险。一般来说，任何避免性传播感染的措施都会降低宫颈癌的风险。
低于平均水平的风险与以下因素有关：
First intercourse deferred until age 18 to 20 or older
Intercourse with only one male partner
避孕套的使用
隔膜的使用
Use of spermicide
包皮环切术和犹太民族在过去被认为是保护因素，现在已知与癌症风险无关（除非它们与性一夫一妻制和婚前禁欲相关）。
Factors associated with higher than average cancer risk are:
以前的CIN（宫颈上皮内瘤变，也称为发育不良）
Genital wart virus infection (some strains)
曾患外阴或阴道癌
Exposure to a male whose previous partner(s) had cervical cancer or CIN
Exposure to a sexual partner who has (or had)阴茎癌
与一个以上的男性性伴侣接触（与一个终生伴侣的女性相比，两个伴侣的风险增加250%；六个伴侣的风险增加600%）
吸烟
DES (diethylstilbestrol) exposure during fetal development
Birth controlpills used four years or more
以前患过疱疹、淋病、梅毒或其他性传播感染
18至20岁之前的首次性交
First pregnancy before the age of 18 to 20
Pap tests are recommended to detect abnormal cervical tissue before it becomes cancerous. The American Cancer Society (ACS) recommends a yearly Pap test along with pelvic exam in women who are sexually active or who are over age 18 (ACS guidelines suggest that after three or more consecutive annual exams with normal findings, the Pap test may be performed less frequently at the discretion of the physician).
Treatment
早期宫颈癌的治疗取决于女性的年龄以及患者和医生的偏好。治疗可能包括冷冻手术、烧灼、锥切、激光治疗或子宫切除术。对于想要孩子的年轻女性来说，锥切术是一种常见的治疗方法。大多数不想多生孩子的女性接受全子宫切除术（切除宫颈和子宫）
Treatment for invasive cancer of the cervix depends on the extent of the disease. Patients whose cancer has invaded only the cervix and those whose disease has extended into the tissues next to the cervix or to the upper vagina can be treated effectively with either surgery or radiation therapy. Surgery may be a total hysterectomy or a radical hysterectomy (removal of the cervix, uterus, upper vagina and the lymph nodes in the area.) Both internal and external radiation therapy can be used to treat invasive cervical cancer.
Patients with cancer that has spread to the pelvis, the lower part of the vagina or to the ureter are treated with radiation therapy alone. Again, both internal and external radiation therapy can be used.
宫颈癌已扩散至膀胱、直肠或身体远端的患者，除接受手术或放疗外，还可接受化疗。Chemotherapy也用于治疗手术或放射治疗后疾病复发的患者。
