Sunday, May 29, 2011

Vaccination for cervical cancer


Primary Prevention  through Vaccination

Gardasil, manufactured under license by Merck & Co. is a vaccine against HPV types 6, 11, 16 and 18. Gardasil is effective up to 98%. It has been received approval from the Food and Drug Administration of 08 June  in 2006. Gardasil was approved in the EU. Cervarix, made by GlaxoSmithKline, was set to 92% effective in prevention of HPV strains 16 and 18  and is effective for more than 4 years. Cervarix was approved in October 16, 2009 United States and the EU in September of 2007, and in other nations. Neither Merck & Co., and GlaxoSmithKline have invented the vaccine. The key stages of vaccine development are claimed by the National Cancer Institute in the United States, the University of Rochester in New York, Georgetown University in Washington, DC, Dartmouth College, Hanover, NH, and the University of Queensland in Brisbane, Australia. Both Merck & Co. and GlaxoSmithKline have licensed patents of all parties.

Together, the types of HPV 16 and 18 currently cause about 70% of cervical cancers. HPV types 6 and 11can cause about 90% of genital wart cases. HPV vaccines have also been shown to prevent the precursors of some other types of cancer by HPV. HPV vaccines are aimed at girls and women ages 9-26, because the vaccine only works if given before infection occurs, and therefore in the public health workers are bound to girls before they begin having sex. The vaccines have been shown to be effective for at least 4-6 years, and is believed to be effective for longer, but the duration of effectiveness, and if a booster is needed is unknown. Men use of the vaccine to prevent genital warts, anal cancer, and to suspend transmission to women or other men must first be considered only on the secondary market. the high cost of this vaccine is a cause for concern. Several countries have or are considering programs to fund the HPV vaccine

Vaccines for cervical cancer are aimed at girls and women ages 9 - 26 ,because only it works if given before infection occurs .And  vaccine affective for atleast 4 - 6 years .



Cervical cancer symptoms - Treatment


Cervical cancer treatment

Microinvasive carcinoma (stage IA) is usually treated by doing hysterectomy (removal of the uterus including all part of the vagina). Stage IA2, the lymph nodes removed. The option for patients who wish to remain fertile is a local surgical procedures, such as a cut-cycle procedure (LEEP) or cone biopsy. If the cone biopsy does not produce clear margins, possible treatment option for patients who wish to preserve fertility is trachelectomy.This trying to surgically remove the tumor while preserving the ovaries and uterus, providing the operation is more prudent hysterectomy.It a viable option for those with stage I cervical cancer has not spread, but is not yet considered standard of care, as few doctors are skilled in this procedure.Even most experienced surgeon can not promise that a trachelectomy can be done only after surgical microscopic examination of the extent of cancer spread.

If there is surgeon is not able to do microscopically confirm clear link of cervical tissue once the patient is under general anesthesia ( GA ) in the theater  ( operating room ), a hysterectomy may still be necessary. This can be done under the same operation if the patient has given consent. Because of the possible risk of cancer spread to lymph nodes in step 1b cancers and some stage 1a cancers, the surgeon may also need to remove some lymph nodes in the uterus in the pathological evaluation.

A radical trachelectomy may be done abdominal or vaginal are differing opinions on what is better.A radical trachelectomy with abdominal lymph nodes, usually only two or three days in hospital, and most women  can recover very quickly (approximately  in six weeks). Complications are rare, even women who think they know after surgery are susceptible to preterm labor and possible late miscarriage. It is generally recommended to wait at least a year before trying to conceive after cervical surgery.Recurrence remaining is very rare if the cancer was removed trachelectomy.

Nevertheless, it is recommended for patients to practice vigilant prevention and follow-up care, including  pap test / colposcopy, and with biopsies of the remaining segment of the uterus below as needed ( every 3 to 4 months for at least five years ) to monitor for any recurrence in addition to minimize exposure to HPV through new safe sex until you actively trying to conceive. Early stages (IB1 and IIA less than 4 cm) may be treated with radical hysterectomy with lymph node removal or radiation. Radiotherapy is given to external beam radiotherapy to the pelvis and brachytherapy (internal radiation). Patients treated with surgery who have high risk features found on pathologic examination are given radiation therapy with or without chemotherapy to reduce the risk of relapse.

The largest early-stage tumors (IB2 and IIA more than 4 cm) can be treated with radiotherapy and cisplatin chemotherapy, hysterectomy (which then usually requires adjuvant radiation therapy) or cisplatin chemotherapy after hysterectomy. Advanced tumors (IIB-IVA) were treated with radiotherapy and cisplatin-based chemotherapy. 15. June 2006, the U.S. Food and Drug Administration approved the use of two chemotherapy drugs, cisplatin and final women's HYCAMTIN (IVB) cervical cancer. Combination therapy is a significant risk of neutropenia, anemia and thrombocytopenia side effects. HYCAMTIN is manufactured by GlaxoSmithKline.



Cervical cancer

Cervical cancer

Cervical cancer is a malignant neoplasm of  cervix or in  the area of cervix. It may be vaginal bleeding but symptoms could be absent until the cancer is at an advanced stage. Treatment included , surgery (including local area excision) in early stages of cancer ,other one is chemotherapy and radiotherapy in advanced stages of cancer.

Pap smear screening can you identify potentially precancerous changes. Treatment of high-level changes may prevent cancer development. In developed countries, widespread use of screening programs for cervical cancer decrease the incidence of invasive cervical cancer by 50% or more. Human Papilloma Virus (HPV) is a significant factor in the development of nearly all cases of cervical cancer.HPV effective vaccines against two strains of HPV that are currently responsible for approximately 70% of cancers of the uterine cervix were registered in the United States, Canada, Australia and the EU.

The cervix is the narrowest part of the uterus where it joins the upper vagina. Most cervical cancers are squamous cell carcinoma ,can arise in the squamous (flattened) epithelial cells lining in the cervix. Adenocarcinoma can originate in glandular epithelial cells are the second most common form of cancer. In very rare cases, cancer may occur in other types of cells in the cervix of the uterus.

Since vaccines only cover some of the carcinogens (high risk) HPV types, women should seek regular Pap tests, even after vaccination.

Causes

Human Papillomavirus (HPV) in high-risk types were found to be essential for the development of cervical cancer. HPV DNA can be detected in almost all cervical cancers. Not all etiologies of cervical cancer is known. Many other factors are involved.

  • Human papillomavirus infection :
In the U.S each year over 6.2 million new HPV infections in men and women, according to the CDC, 10 percent will continue to develop renewable displaysia or cancer of the cervix uterus. That is why HPV is known as cold  sexually transmitted infections worldwide. It is common, affecting about 80 percent of all sexually active people, whether or not symptoms. The factor of greatest risk of developing cervical cancer is infection by a strain of high-risk human papillomavirus. The virus cancer link works by triggering changes in the cells of the cervix that may lead to the development of cervical intraepithelial neoplasia, which could  lead easily to cancer. Women who have multiple sexual partners (or having sex with men who had many partners) have a higher risk.

More than 150 HPV has been recognized (some sources indicate more than 200 subtypes). Of these, 15 are classified as at great risk types (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 73 and 82), 3 as probable high risk ( 26, 53 and 66), and 12 as at lower risk (6, 11, 40, 42, 43, 44, 54, 61, 70, 72, 81, and CP6108). Types 16 and 18 are generally recognized as being responsible for approximately 70% of cervical cancers. Together with type 31, they are the most important risk factor for cervical cancer.

Genital warts are usually caused by different strains of HPV that are not normally associated with cervical cancer. However, it is possible to have more shares in the same time, including those that can cause cervical cancer with those that cause warts. 
The accepted medical paradigm, officially endorsed by the American Cancer Society and other organizations, is that the patient must have been infected with HPV develop cervical cancer, so it is considered a sexually transmitted disease, but Most Women infected with high risk HPV will not develop cervical cancer.Use of condoms reduces, but does not always prevent transmission. Likewise, HPV can be transmitted through skin to skin contact with infected areas. Among men, there is no commercially available test for HPV, but HPV is thought to grow preferentially in the epithelium of the glans penis, and cleaning this area may be preventative.

  • Cofactors
The American Cancer Society offers the following list of risk factors for cervical cancer: human papilloma virus (HPV), smoking, HIV infections, chlamydia infection, stress and stress disorders, factors Dietary, hormonal contraception, multiple pregnancies, exposure to the hormone diethylstilbestrol (DES) and a family history of cancer of the cervix. There is a great possible genetic risk factor associated with the HLA-B7. There was no conclusive evidence to support the claim that male circumcision reduces the risk of members of cervical cancer, although some researchers say there is no convincing epidemiological evidence that men who are circumcised are less likely to be infected with HPV. However, among men with low risk sexual behaviors and monogamous couples, circumcision makes no difference in risk of cervical cancer.

Sign and symptoms

The early stages of cervical cancer could be completely asymptomatic. Vaginal bleeding, contact bleeding or ( very rare ) a vaginal mass can indicate the presence of a malignant tumor. In addition, moderate pain during intercourse and vaginal discharge are symptoms of cancer of the cervix. In advanced disease, metastases may be present in the stomach, lungs or elsewhere. Symptoms of cancer of the cervix uteri advanced may include loss of appetite, weight loss, fatigue, pelvic pain, back pain, leg pain, single swollen leg, heavy bleeding from the vagina, leaking of urine or faeces through the vagina, and fractures.



Diagnosis

Although cytology is an effective screening test, confirmation of the diagnosis of cervical cancer or pre-cancer requires a biopsy of the cervix. This is often the colposcopy, a magnified visual inspection of the cervix aided by using dilute acetic acid (eg vinegar) solution to highlight abnormal cells on the surface of the cervix. Colposcopic impression assessment of disease severity based on visual inspection, which is part of the diagnosis. Other diagnostic and treatment procedures are loop electrical cutting procedure (LEEP) and conization with the inner surface of the cervix was examined pathologically. These are facts, if the biopsy confirms severe cervical intraepithelial neoplasia.

Potentially precancerous lesions :

Cervical intraepithelial neoplasia potential precursor of cervical cancer is often diagnosed at the examination of cervical biopsies by a pathologist. In premalignant dysplastic changes, CIN (cervical intraepithelial neoplasia) grading is commonly used. Designation and grading for cervical precursor lesions has changed several times during the 20th century. World Health Organization classification system was descriptive lesions mention mild dysplasia, moderate or severe or carcinoma in situ (CIS). The term cervical intraepithelial neoplasia (CIN) was developed to focus on the spectrum of abnormalities in these lesions and help normalize treatment.It classified as mild dysplasia CIN 1, moderate dysplasia and severe dysplasia, CIN2 and CIN3 CIS. Recently, CIN2 and CIN3 are combined to CIN2 / 3 These results are what the pathologist can report from a biopsy.


Sub types of cervical cancer

Histological subtypes of invasive cervical cancer are: Although squamous cell carcinoma is cancer of the cervix with the most impact, the incidence of cervical adenocarcinoma has increased in recent decades .

  • Squamous cell carcinoma (80-85% ).
  • Adenocarcinoma (approximately 15% of cervical cancers in the United Kingdom).
  • Adenosquamous carcinoma .
  • Small cell carcinoma .
  • Neuroendocrine carcinoma .
  • Non malignant carcinoma may rarely occur in the cervix .included lympoma and melanoma .
Note uterus include FIGO stage melanoma that does not include the lymph nodes in contrast to the TNM classification for most other cancer condition . For cases  which treated surgically, information collected from the pathologist may use to assign a separate pathologic stage but not to replace the initial clinical phase.