Staging prostate cancer is a process in which doctors categorize the risk of cancer has spread beyond the prostate, or its equivalent, possibly cured by local therapies such as surgery or radiation. Once the patient is placed in a prognostic category, this information may contribute to the selection of the optimal approach to treatment. Staging of prostate cancer can be assessed by clinical or pathological staging methods. Clinical staging usually occurs before the first treatment and tumor presence is determined by imaging and rectal examination, while pathological staging is performed after treatment after the biopsy is performed or the prostate is removed by looking at the cell type in the sample.
There are two commonly used schemes for stage prostate cancer. The most common is enacted by the American Joint Committee on Cancer, and is known as the TNM system, which evaluates tumor size, level of involved lymph nodes, and any metastasis (distant spread) and also takes into account cancer rates. Like many other cancers, these are often grouped into four stages (I-IV). Another scheme used in the past was the Whitmore-Jewett staging, although the performances of TNM were more common in modern practice.
Briefly, Phase I disease is a cancer found accidentally in a small sample when prostate tissue is removed for other reasons, such as benign prostatic hypertrophy, and the cells are very similar to normal cells and the gland feels normal on the examining finger. In Phase II more prostate is involved and lumps can be felt inside the gland. In Stage III, the tumor has spread through the prostate capsule and the lump can be felt on the surface of the gland. In Stage IV disease, the tumor has invaded nearby structures, or has spread to lymph nodes or other organs. The Gleason Assessment System is based on the mobile content and network architecture of the biopsy, which provides an estimate of the destructive potential and ultimate prognosis of the disease.
Video Prostate cancer staging
TNM staging
From the AJCC edition 7 and 7th edition of UICC.
Evaluation of the tumor (primary) ('T ')
- TX : unable to evaluate primary tumor
- T0 : no proof of tumor
- T1 : tumor present, but not clinically detectable or with imaging
- T1a : the tumor is accidentally found at 5% or less of the resected prostate tissue (for other reasons)
- T1b : tumor found accidentally in more than 5% of resected prostate tissue
- T1c : tumors found in needle biopsy due to increased serum PSA
- T2 : tumor may be felt (palpable) during examination, but has not spread beyond the prostate
- T2a : tumor in half or less than half of one of the two prostate glands
- T2b : the tumor is in more than half of one lobe, but not both
- T2c : tumor is present in both lobes but inside the prostate capsule
- T3 : the tumor has spread through the prostate capsule (if only partially, still T2 )
- T3a : the tumor has spread through the capsule on one or both sides
- T3b : the tumor has attacked one or both seminal vesicles
- T4 : the tumor has invaded other nearby structures
It should be emphasized that the designation of "T2c" implies a palpable tumor in both prostate lobes. Tumors found bilaterally on biopsy alone but those that are not palpable bilaterally should not be staged as T2c. Evaluation of regional lymph nodes ('N')
- NX : unable to evaluate regional lymph nodes
- N0 : no spread to the regional lymph nodes
- N1 : has spread to the regional lymph nodes
Evaluation of distant metastasis ('M')
- MX : unable to evaluate distant metastasis
- M0 : no distant metastases
- M1 : there is a distant metastasis
- M1a : the cancer has spread to the lymph nodes outside the regional
- M1b : cancer has spread to the bone
- M1c : the cancer has spread to other sites (apart from bone involvement)
Evaluation of histological value ('G')
Typically, cancer rates (how tissue differences from normal tissue) are evaluated separately from the stage; however, for prostate cancer, level information is used in conjunction with TNM status to classify cases into four whole stages.
- GX : can not rate
- G1 : tumor is very similar to normal tissue (Gleason 2-4)
- G2 : the tumor resembles a normal network (Gleason 5-6)
- G3-4 : tumors resembling normal tissue are virtually nonexistent (Gleason 7-10)
Of note, this system describes tumors as "good-", "quite-", and "bad-" are distinguished by Gleason score 2-4, 5-6, and 7-10, respectively, persisted in SIER and others. database but generally outdated. In recent years pathologists rarely set tumors with levels less than 3, especially in biopsy tissue. More contemporary considerations of the Gleason class are:
- Gleason 3 3: low-grade tumors (favorable prognosis)
- Gleason 3 4/3 5: Most tumors are low grade with some high levels
- Gleason 4 3/5 3: most high-grade tumors with some low levels
- Gleason 4 4/4 5/5 4/5 5: tumors are all high quality
Note that under the current guidelines, if any Pattern 5 is present, it is included in the final score, regardless of the percentage of networks that have this pattern, since the presence of any pattern 5 is considered a poor prognostic marker.
The overall staging
Tumors, lymph nodes, metastasis, and class status can be combined into four stages of worsening severity.
Maps Prostate cancer staging
Whitmore-Jewett Staging
Although it is no longer in general use, the Whitmore-Jewett system is similar to the TNM system and has almost equal stages. Roman numerals are sometimes used in place of Latin letters for all stages (eg Phase I for Stage A, Stage II for Stage B, and so on).
- A : tumor present, but not clinically detectable; found by chance
- A1 : the network resembles normal cells; found in several chips from one lobe
- A2 : wider engagement
- B : tumors can be felt on physical examination but have not spread beyond the prostate capsule
- BIN : tumor can be felt, does not occupy the entire lobe, and is surrounded by normal tissue
- B1 : tumors can be felt and do not occupy the entire lobe
- B2 : tumors can be felt and occupy the entire lobe or both lobes
- C : the tumor has expanded through the capsule
- C1 : the tumor has expanded through the capsule but does not involve the seminal vesicles
- C2 : the tumor involves the seminal vesicle
- D : tumor has spread to other organs
Group risk
While TNM staging is important, a system based solely on anatomical features is not suitable for deciding what treatments are best for patients with prostate cancer, as there is still considerable heterogeneity in prognosis in the staging category. A finer prognosis can be determined by consideration of prostate-specific antigen, and grade (ie Gleason score in the Gleason scoring system). For example, it is now common to classify patients into high, medium and low risk groups based on these three factors (TNM stage, PSA and Gleason score). At present, there is no clear division between stages, which historically represent an anatomical level of disease at diagnosis, and a prognostic model that may include many features that contribute to clinical outcomes.
If treated, patients with low-risk disease are usually treated with active surveillance, prostatectomy, or radiotherapy alone. Patients with medium-risk disease are candidates for prostatectomy or radiotherapy and short duration (less than 6 months) of hormonal ablation (medical castration using gonadotropin-releasing hormone analogues). Although the role of surgery in these patients remains uncertain, those with high-risk illness are usually treated with radiotherapy and long duration of hormonal ablation. Many high-risk patients are not cured by this treatment, and seeking better care in this group is a very stressful concern in prostate cancer research.
References
Source of the article : Wikipedia
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