**3. Pathways of spread**

Most cervical cancers start where the epithelium of the endocervix, frequently columnar, meets the epithelium of the ectocervix, which is especially squamous. As soon as a tumor has broken through the basement membrane, it can either move straight into the cervical stroma or use blood vessels to reach it. Invasive tumors can start as exophytic growths that stick out of the cervix into the vagina or endocervical lesions, which could purpose the cervix to grow very massive, although the ectocervix

#### *Cervical Cancer DOI: http://dx.doi.org/10.5772/intechopen.110131*

seems regular. From the cervix, the tumor can spread to the lower part of the uterus, the vagina, the extensive ligaments in which it could block the ureter, or the uterosacral ligaments, also causing blockage of the ureter. During a pelvic exam, massive tumors may additionally seem fixed. However, an actual invasion of the muscle tissues of the pelvic wall is uncommon. Even though there may be a thin layer of fascia and cell connective tissue between the cervix and the bladder, giant bladder involvement is uncommon in less than 5% of instances. The tumor may additionally spread back to the rectum. However, rectal mucosal involvement at the time of diagnosis is rare. The mucosal, muscular, and serosal layers of the cervix are welldrained by three anastomosing plexuses of lymphatics [13]. The cardinal ligament has a supra-ureteral pathway, and the uterosacral ligament has a dorsal pathway toward the rectal pillars. The vesicouterine ligament drains the upper vagina and bladder and has no lymphatic drainage from the cervix [14]. Three major lymphatic collecting trunks leave the uterine isthmus laterally. The upper branches follow the uterine artery from the anterior and lateral cervix, the intermediate branches drain to the deeper hypogastric (obturator) nodes, and the lowest branches drain posteriorly to the inferior and superior gluteal, common iliac, presacral, and subaortic lymph nodes.

Tumor stage, tumor size, histologic subtype, depth of invasion (DOI), and the existence of lymph vascular space invasion (LVSI) are all associated with the risk of pelvic and para-aortic node involvement. Almost all data on regional nodal metastases come from subjects that had lymphadenectomy as part of radical surgeries earlier than radiation therapy, and those numbers can range significantly. Studies have reported a 15–20% positivity rate for pelvic nodes and 1–5% for para-aortic nodes of patients with stage I disease who underwent radical hysterectomy for their treatment. Depending on many factors, including a physical exam and risk factors, the proportion of patients with positive nodes may be higher than 50% in those with more advanced diseases [15].

Hematogenous metastases are infrequent at diagnosis, and two-thirds of relapsed patients had pelvic disease. Relapses often involve distant metastases. Fagundes et al. found 10-year actuarial rates for distant metastases of 16%, 31%, 26%, and 39% for FIGO stages IB, IIA, IIB, and III radiotherapy (RT) patients, respectively [16]. If pelvic sickness is the first website of relapse, a systematic radiological assessment might not be executed, underestimating these. Lung metastases were the most commonplace extra pelvic region. Although the lumbar spine is a not unusual supply of skeletal metastasis, computed tomography (CT) indicates that women who appear to have isolated metastases may additionally rather have direct tumor extension from PA nodal disease [17].
