Why can't cervical cancer be cured?

cervical cancer

What is cervical cancer? (Cervical cancer)

In cervical cancer, (malignant) cancer cells are found in the uterine tissue (= cervical tissue). The cervix is ​​the opening of the uterus. The cervix (= cervix) connects the uterus (= uterus) with the vagina (= vagina).

In Germany around 4,300 women develop cervical cancer every year. The incidence varies worldwide between five per 100,000 women per year (Spain) and 45 per 100,000 women per year (Colombia). Around 500,000 women worldwide develop cervical cancer every year, with the majority of these women living in third world countries. Around 350,000 women worldwide die from this disease every year.

The median age for cervical cancer is 52.2 years. The age distribution shows a peak between 35 and 39 years and between 60 and 64 years. About 80% of the tumors are so-called squamous cell carcinomas, the rest are adenocarcinomas and the small cell carcinomas. The latter are very rare, but have a very poor chance of recovery.

How does cervical cancer develop?

At the cervix, the mucous membrane of the vagina and the mucous membrane from inside the cervix meet in the so-called transition zone or transformation zone. This is where cervical cancer and its precursors develop. (These diseases are independent of those of the uterine body, such as endometrial carcinoma or uterine sarcoma - see there.) The cause of cervical carcinoma is an infection with human papillomavirus (HPV). Human papillomaviruses (HPV) act as carcinogens at precisely this point on the cervix and in other regions of the lower genital tract (= factors that increase the incidence of malignant tumors).

Infection of the mucous membrane of the transformation zone with human papilloma viruses initially leads to precancerous disease (precancerous stage). Various risk factors, such as B. the sexual behavior increase the risk of disease. Genital HPV types are transmitted through sexual contact, which is why frequent partner changes are one of the risk factors in the development of cervical cancer. Other risk factors for developing HPV infection are:

  • Early birth
  • Suppression of the immune system
  • Hormones
  • Smoke
  • Diet (vitamin deficiency)
  • Genetic predisposition.

Early cervical cancer is not a problem. Only when the tumor is relatively large can vaginal bleeding, weight loss, itching, foul-smelling discharge, or back pain and lower abdominal pain occur.

How is cervical cancer prevented?

Cancer screening forms the basis of prevention. As usual, the doctor will begin by palpating the uterus to look for any enlargement or lumps in the uterus and / or ovaries. This is followed by the so-called colposcopic examination. The doctor looks at the cervix through a magnifying glass with 6-10x magnification. After applying vinegar followed by iodine, he can examine the transformation zone for changes that indicate a precancerous stage or cancer.

Changes in the tissue of the cervix are called dysplasias. In Germany and Europe, the division into mild, moderate, and severe dysplasia is predominantly used. Such changes are also referred to as "cervical intraepithelial neoplasia" (CIN), here a distinction is made between CIN I, II and III. Mild dysplasias often regress, severe dysplasias often remain unchanged and can progress to cervical cancer in 15% of cases.

Next, the "Pap smear" is taken. Cellular material is removed from the cervix with various collection instruments such as cotton swabs and small brushes or wooden spatulas. (Figure 4) The cells are collected and streaked onto a slide, which is then examined for abnormal cells by a pathologist. A distinction is made between different degrees of cell change:

Group I negative

If the diagnosis is group I or II, cytological checks after 6 or 12 months are sufficient. If the diagnosis is group II W (W for repetition), a cytological check should be carried out after specific therapy. Usually this is the treatment of inflammatory changes such as an infection by bacteria or fungi. The diagnosis of Group IIID may have mild or moderate dysplasia. The further procedure here depends on the examination findings. In the case of minor changes, close checks are recommended; if necessary, the doctor may take a small tissue sample from the changed area with biopsy forceps. This is usually painless and is done in a doctor's office. In the case of severe changes, a "conization" is an option. A cone of tissue is removed from the cervix with an electric loop or a laser and examined histologically in a targeted manner. This procedure is usually performed under anesthesia, but it can also be performed under local anesthesia. If such precancerous stages are removed in a healthy person, the patients are cured as a result, but must continue to be monitored regularly, since a recurrence of a precancerous stage is possible in 5 - 10%.

Do you have any questions about cervical cancer screening? Let us advise you in our dysplasia consultation hour.

How is cervical cancer treated?

If carcinoma cells are found in a tissue sample from the cervix, an immediate operation is necessary.

Decisions about the treatment of each cancer patient are usually discussed in an "oncological consultation". Radiologists, radiation therapists, pathologists, gynecologists and internal medicine doctors meet there and discuss the findings and follow-up treatment of each individual patient.

There are three treatment methods for treating cervical cancer:

1st operation (the tumor is surgically removed)

2. Radiation therapy (using high doses of X-rays or other high-energy rays to kill cancer cells)

3. Chemotherapy (drugs are used to kill cancer cells)

surgery

The radical hysterectomy (removal of the uterus) according to Wertheim - Meigs is considered the standard operation for the treatment of stages IB and IIA. Lymph nodes (lymph nodes are small, bean-shaped structures that occur all over the body. They produce and store cells that fight infections) from the pelvis and next to the aorta, as well as the uterus with the uterine ligaments (parametria) are removed. The extent of the parametrium distance is different and individually adapted. A distinction is made between different types of hysterectomy for this purpose. Type III is most often used, with the majority of the mother ligaments and the upper third of the vagina being removed.

With the introduction of the laparoscopy (= laparoscopy), such operations can now be performed without an abdominal incision. Here, gas is first blown under the abdominal wall and then entered into the abdominal cavity with instruments only 5-10 mm wide and operated on. The blood loss, the patient's mobility and the length of hospital stay are more favorable with this approach.

The function of the ovaries can usually be preserved, this depends in part on the histological differentiation of the tumor. In the case of adenocarcinoma and lymph node involvement, ovaries and fallopian tubes should be removed, as these organs can then also show tumor involvement.

In the very early stage I, young women who still want to have children have the option of uterine-conserving surgery - the so-called trachelectomy. Only part of the cervix can be removed with uterine ligaments and the inner cervix including the body can be preserved. This means that pregnancies are still possible.

Complications

If the tumor is larger than 4 cm, surgery should initially be avoided and one of the other options (chemotherapy and radiation) to reduce the size of the tumor should be sought. If necessary, a subsequent operation can be discussed after completion of these therapies.

Irradiation

For stages III and IV, radiation is the method of choice.

Radiation therapy uses high-energy X-rays to kill cancer cells and shrink tumors. In external radiation therapy (percutaneous radiation), the rays come from a machine outside the body. In internal radiation therapy or "afterloading therapy", they come from radioactive material (radioisotopes) that is inserted through small plastic tubes into the area where cancer cells are found. The radiation can be carried out alone or together with an operation and / or chemotherapy. Both radiation methods can also be administered together.

Radiation therapy is often used to stop bleeding and relieve symptoms.

Complications

chemotherapy

Chemotherapy, also known as "systemic therapy", uses drugs to kill cancer cells. Chemotherapy can be taken in pill form or given directly into the body as an infusion through a vein. The drugs enter the bloodstream, travel around the body, and destroy cancer cells outside the uterus.

In recent years, neoadjuvant chemotherapy (i.e. chemotherapy before surgery or chemotherapy alone) has been established. As already described above, this procedure is mainly used for inoperable tumors in stage IB2 (more than 4 cm in diameter). A tumor reduction can be achieved in approx. 60-70% of the cases, so that a "radical hysterectomy" can be performed after two to three cycles of a combination therapy with bleomycin. In stage IB tumors with a tumor volume of more than 60 cm3, this also seems to improve the survival rate significantly.

If chemotherapy is used for advanced and inoperable cervical cancer, response rates between 15 and 35% are given for the various schemes.

Chemotherapy can also be used successfully together with radiation.

The side effects vary depending on the drug. Hair loss, nausea, vomiting, skin problems, sensory disorders in the hands and feet, and a reduction in blood cells can occur.

How is the extent of the disease determined?

The prognosis (prospect of cure) and the choice of treatment method depend on the stage of the cancer (whether it is confined to the cervix or has spread to other parts of the body) and the general health of the patient.

Staging

Carcinoma in situ means that the cancer was discovered at a very early stage. Abnormal cells are only found in the uppermost layer of the lining of the cervix and have not invaded the deeper layers.

Stage I: The tumor is only limited to the cervix.

  • Stage IA: only a small amount of tumor is found under the microscope (max. 5 mm deep and 7 mm wide)
  • Stage IB: a larger tumor mass can be seen without a microscope, but the tumor is limited to the cervix

 

  • Stage IIA: without spreading to the maternal ligaments
  • Stage IIB: with spread to the maternal ligaments

 

  • Stage IIIA: The tumor spreads to the lower third of the vagina, but not to the pelvic wall
  • Stage IIIB: spread of the tumor to the pelvic wall

 

  • Stage IVa: spread to neighboring organs
  • Stage IVb: spread to distant organs

 

In principle, cervical cancer can spread in four ways.

What is the course of the disease and what does it depend on?

The prognosis or the course of a tumor depends not only on the size of the tumor but also on the involvement of the lymph nodes. The higher the stage of a tumor, the higher the likelihood that lymph nodes will be affected. Regardless of the stage, patients with negative lymph nodes have a 5-year survival rate of 90%, with positive lymph node involvement only between 20 and 60%.

The 5-year survival rate for stage I is 85% regardless of the type of treatment - irradiation or surgery. The higher the stage, the higher the risk of developing a relapse; this is six times higher for stage IIIB than for stage IB. 10-42% of patients operated on for cervical cancer develop a relapse. If a relapse occurs, 80% of this happens during the first 2 years.

Bone and lymph node metastases each occur in 6% of patients with cervical cancer.


What can be done if the disease recurs?

If a tumor occurs after a previous operation, radiation with chemotherapy is the method of choice.

If a relapse occurs after radiation or a combination of radiation and chemotherapy, only surgical treatment remains. This involves removing part of the rectum or the bladder (depending on where the cancer has spread) along with the cervix, uterus, and vagina. This is called an "exenteration". An artificial anus and a new bladder are created. If the vagina is also removed, the patients have to undergo plastic surgery in order to have an artificial vagina designed after this procedure, which is nowadays possible without any problems. Before such operations, a detailed discussion takes place between the doctor and the patient.


How should women with cervical cancer be examined?

After developing cancer, patients remain under close control. The clinical examination takes place during the first two years after treatment at three-month intervals in order to rule out a recurrence in the area of ​​the vagina or the vaginal closure. Some of these recurrences can be treated curatively (curable).

 

You can also find more information about treatment on the website of the dysplasia center.