Prostate cancer: How does it affect the body, and what's a Gleason score?

What is prostate cancer?

Speaking to PhilSTAR L!fe, Dr. John Ivan S. Alonzo, an expert on General Urology and Urologic Oncology, said that prostate cancer is a disease involving the growth and spread of abnormal cells arising from the prostate gland, a walnut-shaped organ found below the urinary bladder in the male reproductive system.

"Men aged 60 years and above are usually affected by this kind of cancer," he noted. 

Dr. Andrew Valdez, a urologist and men's health advocate, also added that prostate cancer is a disease in which the cells of the prostate gland multiply and grow out of control.

"Cancer cells do not behave like normal cells—they abnormally develop genetic changes and mutations, which allow them to multiply uncontrollably. This rapid growth will then overwhelm and displace healthy cells, causing harm to the body," he said. 

Valdez added that pathologists identify prostate cancer cell patterns by viewing tissue samples under a microscope for “Gleason patterns,” which are used to compute the Gleason score and the Grade Group.

"If under the microscope, the pattern of cells looks normal or closer to healthy cells, they are given a lower Gleason pattern number. On the other hand, if the patterns look more abnormal, they will garner a higher number," he explained. 

Alonzo, meanwhile, said that patterns are graded from six to 10. "The higher the grade, the more aggressive the prostate cancer."

"A low Gleason score means the prostate cancer is less likely to grow and spread quickly, as opposed to prostate cancer with a higher Gleason score," Valdez added.

Biden's prostate cancer, which has a Gleason score of 9, is classified as high-grade.

"These cancers are very aggressive and are known to grow and metastasize rapidly," Valdez added. Metastasis happens when cancer cells enter the bloodstream and spread to other parts of the body— in the former president's case, it has spread to his bones.

Prostate cancer is the third most common form of cancer in males, with 9,764 cases in 2022, according to the Global Cancer Observatory.

According to Valdez, most patients with the disease are diagnosed when they reach 65 years old.

Apart from age, genes also raise the risk of prostate cancer. "Having a close family member with prostate cancer—a sibling or a parent—increases the chance of a patient also having prostate cancer, as having the genes BRCA1 and BRCA2 predisposes patients to hereditary prostate cancer."

Is it treatable?

When prostate cancer is detected early, before it spreads outside the prostate, patients have a high likelihood of full recovery. In localized cases, Alonzo said that nearly all patients survive at least five years following treatments involving surgery, radiation therapy, hormonal manipulation (i.e. Androgen Deprivation Therapy or ADT), or a combination of these modalities. However, the five-year survival can drop to as low as 30% in patients with metastatic prostate cancer.

Treatment, according to Valdez, depends on whether the cancer is in the early stages or already advanced. 

"The good news is that early-stage prostate cancer is treatable and curable," he said.

In advanced prostate cancer cases, he said that the focus shifts "from cure to managing the disease and its manifestations." The primary goal is to slow down the cancer growth, alleviate symptoms (including treatment-related symptoms), and improve quality of life. 

"Patients may still be offered hormonal therapy, chemotherapy, targeted therapy, and some are enrolled in clinical trials where novel therapies are offered," he said. 

However, in metastatic prostate cancer, or when cancer spreads to organs like bones or lungs, the disease is harder to control. Hence, ADT becomes the central treatment since it slows cancer growth by reducing male hormone (androgen) levels that fuel the cancer.

"Other medications are added to ADT in this setting in order to prolong patient survival," Alonzo explained. 

Signs and symptoms

In its early stages, prostate cancer often does not present with noticeable symptoms, which is why routine screening and awareness are crucial for early detection and treatment. 

"The devious thing about prostate cancer is that it’s often asymptomatic for a long time, until it is in its advanced stages," Valdez said, enumerating some of the symptoms of prostate cancer including difficulties in urinating, urinary frequency, peeing blood, burning sensation when peeing, bone pains, lower back pain, and unexplained weight loss.

Likewise, Alonzo said symptoms for prostate cancer may present with lower urinary tract symptoms associated with benign prostate enlargement, since the two can co-exist in the same patient.

A biopsy, when warranted, will make a definitive diagnosis, especially as prostate cancer shares the symptoms of benign prostatic hyperplasia (BPH), making it difficult to tell the difference between the two conditions just by symptoms, Valdez said.

Is prostate cancer avoidable? 

Alonzo shared that, unfortunately, there are currently no established modifiable risk factors for prostate cancer, meaning "you can't do anything in particular to avoid it."

While research continues into potential causes and risk-reducing behaviors, the key to managing prostate cancer, the urologist said, lies in early detection.

"Prostate cancer screening is recommended in men aged 45 to 72 years old and should be started earlier in those with a strong family history of prostate cancer," he explained. 

"Screening is done at least annually by a well-trained urologist and involves history taking, a physical exam which includes a digital rectal exam (DRE), and serum PSA (prostate-specific antigen) determination," Alonzo added. 

Meanwhile, embracing a healthier lifestyle may ease the risk of having prostate cancer. According to Valdez, this would entail avoiding processed food and sugars, increasing fiber intake, staying hydrated, maintaining a healthy weight, exercising regularly, and not smoking and drinking.