What is prostate cancer?

Prostate cancer develops in the prostate gland, which is found exclusively in males. It is situated between the urinary bladder and the penis and in front of the rectum.

Cancer occurs when the genes of a cell become abnormal (the cells mutate to become cancer cells), causing the cells to multiply and interfere with the normal function of a tissue.

Cancer of the prostate is a common type of cancer in men and can be treated well in the early stages.

The malignancy in the prostate begins when its healthy or normal cells proliferate rapidly to form a growth.

Prostate cancer is somewhat different than other types of cancer because its tumors do not spread quickly as other cancers do.

They grow very slowly and may not cause any symptoms for years. Even after they have metastasized, they are easy to manage for a long period.

The most common type of cancer found in the prostate is adenocarcinoma. It is slow-growing and typically occurs in the posterior lobe of the prostate. Other less common types, neuroendocrine prostate cancer, and small cell prostate cancer are more aggressive and spread early.

According to Advances in Human Biology, 70% of prostate cancers are from the peripheral zone, 20% from the transition zone, and 10% from the central zone of the prostate.

Prostate cancer and age factor

The risk of prostate cancer increases with age, especially after age of 50 years. Around 60% of the cases are diagnosed in people who are 65 or older. Older adults with this disease can face problems with regard to treatment.

Prostate cancer is more likely to develop in older men and in non-Hispanic Black men. It is rare in men under 40 years of age. About 6 out of 10 men diagnosed with this cancer are 65 years of age or older.

The incidence of prostate cancer is directly related to the age of the man. Nearly 75 percent of the diagnosed global cases occur in men over 65 years of age.

According to the American Society of Clinical Oncologists, prostate cancer is twice more likely to develop  in men over 70 years than in younger people. They’re also more than four times as likely to have advanced prostate cancer. And they’re more likely to die from the disease.

Statistics of figures and mortality rates

  • Prostate cancer is more common in southern and eastern Asia, Europe, North America, Australia, and New Zealand.
  • It is the fourth most common cancer after skin, breast, and lung cancers worldwide.
  • It is the second most commonly occurring cancer in men after lung cancer.
  • About one man out of eight men will be diagnosed with prostate cancer in his lifetime.
  • According to World Statistics in 2012, this cancer accounts for 15% of men’s cancers and the second leading cause of cancer death in men.
  • Annually, about 300,000 new cases are diagnosed of which nearly 41,000 succumb to it.
  • More than 50% of deaths from this cancer have occurred in developed countries.
  • With a mortality of 6.7 per 100,000, this cancer is the sixth cause of death from cancer in men.
  • Incidence and mortality rate of prostate cancer in different countries: The highest incidence was related to France, Guadeloupe, France, Martinique, and Ireland, respectively. The highest mortality rate was in Barbados, Jamaica, and Benin, respectively.
  • Human development index (HDI) and prostate cancer: Recent studies indicate that the number of newly diagnosed cases is rising in countries with a high HDI. However, mortality rates in these countries are lower than in countries with lower HDI (such as African and Caribbean countries). This is mainly due to easier access to screening and treatment in countries with a high  HDI. High mortality from prostate cancer in African and Asian countries is due to late detection of its advanced stages.
  • The American Cancer Society’s estimated projections in the United States for 2021 are:
    • About 248,530 new cases
    • About 34,130 deaths

What causes prostate cancer?

Research still has not found the answer to this question and we do not know how cancer of the prostate develops.

Broadly, however, we know that cancer is caused due to changes in the DNA of a normal cell. DNA is the chemical in our cells that constitute our genes and control how the cells behave and function.

We have oncogenes and tumor-suppressing genes.

  •  Oncogenes control cell growth, cell division and also keep the cells alive.
  • Tumor suppressing genes keep cell growth under control, repair any wrong changes in DNA, and cause cellular death after the right duration.

Cancer is caused by DNA mutations (changes) that either continuously keep the oncogenes turned on or turn off the tumor suppressor genes.

This leads to the cells growing and multiplying fast and out of control and forming cancer cells, which ultimately form a malignant tumor.

DNA changes can either be inherited from a parent or can be acquired by a person during his life. Some genes mutate during a person’s lifetime, and the mutation is not inherited by the children.

These are called acquired mutations and are mostly responsible for the development of prostate cancer. Inheritance plays very little or no role in the development of this cancer.

Things that we are exposed to in our environment, including cigarette smoke, radiation, hormones, and diet can cause acquired mutations. These are the risk factors that predispose you to cancer.

Risk factors

While prostate cancer can develop in any man, there are certain factors that increase your risk of developing it.

However, if you are associated with one or more of these risk factors, it does not mean you will develop this cancer. There are many examples to show this. Again, there are men who develop cancer and have no such associated risk.

  • Older age. The risk increases as your age advances and is high after the age of 50 years. About 99% of the cases occur after the age of 50 years. About 60% are diagnosed in men who are above the age of 65 years.
  • Family history. Prostate cancer that occurs in a family is called familial prostate cancer. The explanation given for this cancer risk is shared genes, shared environmental factors, and a common risky lifestyle. Familial cancer is rare and accounts for 5% of all cases. This hereditary predisposition develops when the acquired mutation by the first generation is passed down from one generation to the next. You may want to go in for genetic testing to see whether you have inherited mutations that might increase your cancer risk. However, you should know that inherited genetic mutation doesn’t necessarily make you prone to cancer.
  • Certain ethnicities or race. Prostate cancer is more common in black males than white males. Asian and Hispanic males are at the lowest risk among the Americans with a lower risk than black males or white males.
  • Obesity. Though obese men show a lower risk of getting low-grade cancer of the prostate, they are more prone to develop an aggressive form of prostate cancer. We still do not know the reasons for this. Some studies have also indicated that obese men may be at greater risk of suffering from more advanced prostate cancer and of dying from it. However, all studies do not confirm this, and more research is required to connect obesity as a risk factor.
  • Genetic changes. Several genetic mutations that you have inherited increase your cancer risk. For example,
      • Inherited mutations of the BRCA1 or BRCA2 genes that increase your breast and ovarian cancers in women also increase can also increase prostate cancer risk in men.
      • Lynch syndrome is an inherited condition that increases your risk of colon cancer, endometrial cancer, and prostate cancer.
  • Diet. Epidemiologic studies conducted to date have revealed that some dietary habits alter the risk of advanced prostate cancer. According to NIH, the regular consumption of high saturated fat foods, meats, and calcium increases your risk. Studies also showed that fish and zinc intake had no such associated risk.

Symptoms and warning signs

There are many symptoms that present with prostate cancer. Different men have different manifestations while some men present no symptoms at all.

The symptoms and early warning signs may include:

  • Increased frequency of urination more so at night
  • The urine flow is weak and you may need to strain to empty the bladder
  • Difficulty in starting urination or stopping it
  • There may be blood in the urine or in the semen
  • Sudden onset of erectile dysfunction
  • Burning micturition may or may not be associated with pain
  • Discomfort or pain when sitting

Benign hyperplasia of the prostate (BPH) can also cause such symptoms and so can urinary bladder infection.

Once such symptoms arise, it is enough for your doctor to start the diagnostic process to rule out or confirm the diagnosis.

Relieving symptoms with supportive and palliative care remains an important part of treatment and it is implemented immediately and throughout the cancer treatment.