Cancer that affects the anus and surrounding regions is called anal cancer. The anus is the region that connects the rectum to the outside of the body. The function of the anus is to allow stool to pass out from the body. In anal cancer, a tumor develops in the anal region through the unlimited growth of abnormal cells in this area. Cancer cells can form from the cells that line the anal canal, called squamous cell carcinoma, or they can form from the skin cells in the anal region. Both of these types of anal cancer are usually treated differently. Standard treatment methods for cancer use surgery, radiation therapy, and chemotherapy. Typically, a combination of these three approaches is used for anal cancer treatment. The specific combination is recommended based on the stage of the cancer and location of the tumor cells.
Are there any signs of anal cancer?
Now that you know what is anal cancer, you’re probably wondering how to detect it. The typical signs and symptoms of anal cancer include bleeding in the anus or rectum, pain in the anus, anal itching, lymph nodes swelling in the anus, changes in bowel movements, discharge from the anus, and a growth or lump in the anus.
How common is anal cancer?
Anal cancer is uncommon compared to other types of cancer. About one in 500 people will develop anal cancer during their lifetime. In comparison, about one in eight women will develop breast cancer during their lifetime. Moreover, anal cancer is often confused with colorectal cancer, but these are two separate conditions. An estimated one in 20 people will develop colorectal cancer, showing how this type of cancer is much more prevalent than anal cancer.
According to the global statistics collected by the World Cancer Research Fund by the American Institute of Cancer, anal cancer ranked as the 29th most common cancer in 2018 with a total of 48,541 new cases diagnosed that year. The amount of new cases accounted for only 0.3% of all newly diagnosed cases of cancer. If broken down by gender, anal cancer had the lowest incidence in men globally in 2018 with 20,196 new cases that year. In women, anal cancer was also more rare and ranked as 24th most common out of 31 types of cancer in 2018. About 28,345 women were diagnosed with anal cancer that year.
Who can get anal cancer?
Anyone can get anal cancer, but the presence of certain risk factors that are known to be what causes anal cancer increase the likelihood of developing the disease. People who are infected with human papillomavirus (HPV) are at much higher risk of developing anal cancer. It is estimated that up to 90% of all cases of anal cancer are associated with HPV infection. People who smoke, have a weakened immune system, have multiple sex partners, or engage in receptive anal intercourse, are also at increased risk for anal cancer. Anal cancer is more common in women than in men.
What is the survival rate for anal cancer?
If you are diagnosed with anal cancer, one of the biggest questions that may arise is what the survival rate is like for the disease. The survival rate is an estimate of what percentage of patients with the disease are still alive five years after diagnosis. This estimate is based on patients that have the same type of cancer and are at the same stage of the disease. Every type of cancer has a different survival rate. Even subtypes within the same category of cancer that affect the same body part have a different survival rate.
Importantly, the survival rate cannot be used to predict how long a cancer patient will live, as everyone responds differently to treatment, and tumors behave differently within the body depending on the patient’s medical history. However, the survival rate can give you an idea of whether standard treatment is likely to be successful, as it is reflective of how many patients with the disease respond to treatment.
According to the American Cancer Society that obtains its statistics from the SEER (Surveillance, Epidemiology, and End Results) Database of the National Cancer Institute, survival rates for anal cancer are divided into three sections depending on whether the disease is localized, regional, or distant.
- Localized anal cancer is confined to the anal area, and the primary tumor has not spread to surrounding tissues or to distant regions. Only about 48% of all anal cancer cases are diagnosed this early, but the anal cancer prognosis at this stage is good with a survival rate of 82%.
- Regional anal cancer refers to cancer in the anal region that has spread to nearby tissues and/or nearby lymph nodes (Stage III). At this stage, the disease has a five-year survival rate of 65%.
- Distant anal cancer is when the cancer has spread to distant organs such as the lungs or brain (Stage IV), which is also called distant metastases. The anal cancer prognosis is worst in Stage IV with a five-year survival rate of 32%.
- Overall, if all three groups are combined the average survival rate for anal cancer is 68%.
These five-year survival rates are also collected every five years, so they do not take into account any advances in anal cancer treatment or diagnosis that can happen within the span of five years. So, these numbers are just an estimate, and a cancer patient may not necessarily fit in with these statistics if they respond better or worse to treatment based on their individual constitution. These numbers also only apply to cancers that occur the first time and not for recurrent anal cancer in which treatment was not completely successful the first time.
Factors that affect the survival rate of anal cancer
Many prognostic factors affect the overall survival of anal cancer patients.
Type and Stage of Cancer
Based on the survival rates listed above, it’s clear that the stage of the cancer is an important prognostic factor in how long a patient is likely to survive with treatment. Earlier stage cancers in which the primary tumor is still localized have a much better prognosis than later stage III or IV anal cancer. Once the cancer cells spread to other parts of the body and metastatic anal cancer occurs, the overall survival rate worsens. Additionally, a squamous cell carcinoma, the most common type of anal cancer, tends to respond to treatment differently than the skin cancers in the anal region, such as melanomas.
Time of diagnosis
An early diagnosis makes a large difference in the survival rate of cancer. If a cancer is diagnosed at an earlier stage, treatment can often successfully cure it, even without recurrence happening. This is why it is important to have regular checkups with your doctor, especially if you notice symptoms such as anal bleeding or itching. Many people tend to assume that these symptoms are due to less serious problems like hemorrhoids and avoid being examined.
Preventing risk factors
Whether you will get cancer is hard to predict, but you can do certain things to reduce the risk of developing anal cancer.
- HPV vaccination can protect against HPV infection, which increases your likelihood of both anal cancer and other types of cancer such as cervical cancer. The vaccination has an age limitation though, so check with your doctor whether you are eligible for it.
- Quit smoking. The incidence of anal cancer is higher in smokers.
- Practice safe habits during sexual activity. This can protect you from HPV infection, and in turn, from developing anal cancer.
You can find more about anal cancer here and reach out to us for a free consultation at the Immunity Therapy Center to find out how we can help in the treatment of anal cancer.
At Immunity Therapy Center, our goal is to provide objective, updated, and research-based information on all health-related topics. This article is based on scientific research and/or other scientific articles. All information has been fact-checked and reviewed by Dr. Carlos Bautista, a Board Certified Medical Doctor at Immunity Therapy Center. All information published on the site must undergo an extensive review process to ensure accuracy. This article contains trusted sources with all references hyperlinked for the reader's visibility.