Tumor size and Prostate Cancer Death Rate
Prostate cancer is one of the leading causes of morbidity and mortality in men. The pathophysiology of prostate malignancy revolves around abnormal extra-mitotic division of cells that may compromise the normal functioning of prostate gland. It is imperative to mention that the lifetime risk of developing prostate malignancy is 14% (1). Based on latest statistics, age-adjusted mortality rate due to prostate malignancy is 21.4 per 100,000.
In order to assess and stage the malignancy, several classification criteria are used such as gleason scoring, PSA levels etc. This is mainly because correct diagnosis and staging of the disease is one of the key step in the treatment process.
AJCC TNM Staging System
This is one of the most widely accepted staging systems to assess individual cases of prostate cancer. The system is proposed by AJCC (American Joint Committee on Cancer). The mortality and morbidity rate of prostate cancer is dependent largely on the stage of prostate cancer and size of tumor. Staging of prostate cancer through TNM systems follows this basic criteria:
- T: Identifying the extent of tumor
- N: the extent of lymph nodes involved in the cancer
- M: to check if the disease has metastasized or not
- Determination of PSA level at the time of diagnosis
- Gleason score
Types of Staging
Prostate cancer can be staged into two different types
- Clinical stage: The clinical stage of the disease is usually assessed by a health care practitioner via physical and imaging tests such as prostate biopsy, radiography etc.
- Pathologic stage: The pathologic stage is determined after the patient undergoes the surgical procedure. The results of pathologic stage are helpful in determining the stage of malignancy and ascertaining the appropriate type of treatment.
T categories
There are four categories (ranging from T1-T4).
- T1 type
As discussed above T type is to identify the extent of tumor
The subtypes of T type includes,
T1a | In T1a the cancer is diagnosed accidentally while performing TURP (transurethral resection of prostate). This test is specifically done to diagnose BPH (benign prostate hyperplasia). |
T1b | It is also diagnosed during TURP. |
T1c | The cancer is diagnosed after the biopsy is performed which is generally recommended to ascertain the cause of high PSA levels |
- T2 type
Larger tumors that are usually identified on ultrasound are classified under T2 type.
T2a | The cancer has spread to only either half of the prostate (right or left). |
T2b | The cancer has spread to more than half of the prostate. |
T2 | The cancer cells have spread to the entire prostate gland. |
- T3 type
T3 type is more aggressive and locally advanced and suggests progression of cancer to seminal vesicles and surrounding tissues.
T3a | T3a suggests progressive disease that has not yet spread to seminal vesicles |
T3b | T3b indicates that cancer has progressed to seminal vesicles. |
- T4 type
T4 suggests advanced disease. The morbidity and mortality is generally high as cancer cells spread to urethral sphincters, bladder and distant tissues.
N category
N category is used to assess the involvement of lymph nodes. Nodal involvement suggests advanced disease and higher morbidity and mortality.
NX | No lymph node involvement. |
N0 | The cancer progression has started but the surrounding lymph nodes are not yet involved. |
N1 | The cancer has spread to draining lymph nodes. |
Involvement of lymph nodes can greatly influence the treatment and management decisions.
M category
M refers to distant tissue metastasis in the setting of prostate cancer. Some common areas where prostate cancer cells can metastasize include liver and lungs.
The subtypes include,
M0 | Lymph nodes are not involved |
M1
| The cancer cells spread to involve near-by lymph nodes. The cancer has advanced to involve near-by tissues and lymph nodes of pelvic region The prostate cancer has metastasized to bones Other functional organs such as liver and lungs are involved. M1c is associated with high mortality and poor overall prognosis. |
Stage grouping
Based on the findings of T, N and M analysis, the physicians assess the stage of cancer using PSA levels. In situations where PSA levels are not available; the staging can be done on the results of TNM analysis alone.
Stage 1
T1 (this may range from A-C) |
N0 (i.e. no nodal involvement) |
M0 (i.e. no signs of distant metastasis) |
PSA is less than 10 |
Gleason score is 06 or less than this. |
OR
T2a |
N0 (i.e. no nodal involvement) |
M0 (i.e. no signs of distant metastasis) |
PSA less than 10 |
Gleason score or 06 or less |
T1 |
N0 (i.e. no nodal involvement) |
M0 (i.e. no signs of distant metastasis) |
PSA level less than 20 |
Gleason score equals to 07 |
OR
T1 |
N0 (i.e. no nodal involvement) |
M0 (i.e. no signs of distant metastasis) |
PSA levels are in range between 10 and 20 |
Gleason score less than 06 |
OR
T2a or T2b |
N0 (i.e. no nodal involvement) |
M0 (i.e. no signs of distant metastasis) |
PSA is less than 20 |
Gleason score is equals to or less than 07 |
Stage II b
T2c |
N0 (i.e. no nodal involvement) |
M0 (i.e. no signs of distant metastasis) |
PSA in any range |
Gleason score in an range |
OR
T1 or T2 |
N0 (i.e. no nodal involvement) |
M0 (i.e. no signs of distant metastasis) |
PSA is equals to or more than 20 |
Gleason score in any range |
OR
T1 or T2 |
N0 (i.e. no nodal involvement) |
M0 (i.e. no signs of distant metastasis) |
PSA in any range |
Gleason score equals to or more than 08 |
Stage III
T3 |
N0 (i.e. no nodal involvement) |
M0 (i.e. no signs of distant metastasis) |
PSA in any range |
Gleason score in any range |
Stage IV
T4 |
N0 (i.e. no nodal involvement) |
M0 (i.e. no signs of distant metastasis) |
PSA in any range |
Gleason score in any range |
OR
Any type of T |
N1 |
M0 (i.e. no signs of distant metastasis) |
PSA in any range |
Gleason score in any range |
Survival rate
According to recent estimates the survival rate of prostate cancer is usually high if appropriate treatment options are sought early in the course of disease.
- 5 year survival rate is 100 percent
- 10 year survival rate Is 99 percent
- 15 year survival rate is 94 percent
Relative Survival Stages at the Time of Diagnosis
According to latest statistics, more than 2,795,592 men are currently living in United States with prostate cancer; yet estimated number of deaths due to prostate cancer in the year 2015 is 27,540 (or 4.7% of all cancer deaths).
- Local stage
The local stage indicates that the cancer has not progressed to any area outside of the prostate gland; the survival rate in local stage is approximately 100 percent. Most of the cases are diagnosed in this stage.
- Regional stage
In this type, the cancer advances to the surrounding tissues around the prostate gland. The survival rate is approximately 100 percent if treatment is sought early.
- Distant stage
This is the most advanced stage of prostate malignancy in which the cancer cells invade lymph nodes and distant organs (hence also referred to as Intravenous cancer). The survival rate is 28 percent.
References:
1. http://www.cancer.org/cancer/prostatecancer/detailedguide/prostate-cancer-survival-rates