Growth and spread of prostate cancer
Prostate cancer usually grows very slowly, first within the prostate. Then he can break through the capsule and proceed locally. From a certain size metastases are possible, preferably in the lymph nodes and skeleton. The spread is measured by the TNM system.
The growth rate of prostate cancer is very low. At a constant rate of cell division, this means that it takes many years for a single, tiny cancer cell a small tumor has grown up, which then, however, no longer taking so long to evolve over a possibly palpable node to spread cancer on.
So it is now believed that latent prostate cancers (see genesis and forms , "sleeping cancer") constitute a special form, but early forms, so incurred only late and are no longer noticed during his lifetime. Unknown, however, is why these as opposed to the clinically detectable tumors in almost all population groups equally often occur (see frequency ). Apparently arise in all groups the same number of cancers, but the further growth accelerated only in some groups and not even there at all men for unclear reasons.
Spread
From its place of origin, mostly in the peripheral zone, the tumor spreads initially preferred downward toward prostate tip (apex) of, or to the other zones (locally limited prostate cancer; into the zones see Anatomy ). Then he can break through the prostate capsule, particularly along the penetrating vessels and nerves, and in the neighboring organs such as seminal vesicles, bladder, rectum or pelvic waxing (locally advanced prostate cancer).
Metastases (secondary tumors) usually arise first lymph (via the lymphatic vessels), later hematogenous (via the blood). The first lymph nodes (regional lymph nodes) lie in the pelvis (in the so-called obturator fossa), another in front of the sacrum, in the groin and along the large blood vessels in the pelvis, abdomen and chest. The hematogenous spread rarely affects the internal organs, but often the skeleton, particularly the first lumbar vertebrae, femur and pelvic bone.
In addition to the type (s classification ) mainly determined the size of the prostate or spread.Thus only will tumors from a volume of 0.2 cc (diameter 0.7 cm, just palpable in favorable seat) can metastasize, whereas it was more than 12ccm (diameter 2.8 cm) is almost always the case.And among 4ccm (diameter 2.0 cm) is a capsule breakthrough unlikely.
TNM system
The spread of prostate cancer can be detected with the TNM system: T stands for the primary tumor, N for lymph nodes in the area (regionär) and M for distant metastases (outside the regional lymph nodes). These categories are further specified with numbers and letters (see table and figure).
The classification is very important for the choice of therapy (see treatment planning ). The basic procedure is based on the findings from clinical and technical studies (see study ). In this case, the studied category c (= engl. Clinical) are prefixed (eg T2a N0 M0 or cT2a cN0 cM0).
After histological (histological) examination of tissue removed (eg after radical prostatectomy ) of the relevant category is a p (= secured pathological) prefixed (eg PT2A pN0 M0). In addition, it adds a further category of R, which stands for a somewhere in the body remaining residual tumor: R0 = no evidence, R1 = microscopically visible (eg if the cut edge is affected by the tumor), R2 = macroscopic (visible to the naked eye) is visible. Both new information easier to estimate the prognosis.
In determining whether the respective highest applicable category is relevant (eg smaller, but by breaking capsule = pT3a tumor, metastases to bone, but also in the liver = M1c). A tumor that only in the prostate biopsy, but not by palpation ( DRU is found) or imaging techniques, is always classified as T1c, even if it affects both sides of the prostate. One possible therapy (eg the removal of the tumor) does not lead to demotion.
. Chart: TNM system for prostate cancer, see text for explanations (according to UICC, 7th edition 2009; additional: A0 to D2 = classification according to the American Whitmore-Jewett system)
| T | Primary tumor | ||
| TX | Not to judge | ||
| T0 | Not available (no evidence of primary tumor; A0) | ||
| T1 | Not clinically apparent (neither palpable nor visible by imaging procedures) | ||
| T1a | Randomly found in tissue removed (incidental tumor), in 5% of the tissue or less (A1) | ||
| T1b | Randomly found in tissue removed (incidental tumor), in more than 5% of the tissue (A2) | ||
| T1c | By needle biopsy (eg because of elevated PSA) diagnosed (B0) | ||
| T2 | Confined to the prostate | ||
| T2a | In more than half of one lobe of the prostate (prostate page; B1) | ||
| T2b | In more than half of a prostate lobe (B2) | ||
| T2c | In both prostate lobes (B3) | ||
| T3 | Spread through the prostate capsule | ||
| T3a | One or both sides (C1/C2) | ||
| T3b | In the seminal vesicle (s) grown (C2) | ||
| T4 | Waxed other neighboring structures than the seminal vesicles (eg, bladder neck, external sphincter, rectum, pelvic floor muscles, pelvic wall; C3) | ||
| N | Regional lymph nodes (lymph nodes in the area) | ||
| NX | Not to judge | ||
| N0 | Not infested (no evidence of regional lymph nodes metastases) | ||
| N1 | Infested (regional lymph nodes metastases present, D1) | ||
| M | Distant metastases | ||
| M0 | Not available (no evidence of distant metastases) | ||
| M1 | Available (D2) | ||
| M1a | In non-regional lymph nodes | ||
| M1b | In bone | ||
| M1c | In other parts of the body |
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