THE SIGNIFICANCE OF HISTOLOGICAL SUBSTAGING IN CURATIVE THE SIGNIFICANCE OF HISTOLOGICAL SUBSTAGING IN CURATIVE

RESECTED T3 COLORECTAL CANCERRESECTED T3 COLORECTAL CANCER

Karl Mrak & Jörg TschmelitschKarl Mrak & Jörg Tschmelitsch

Department of Surgery, Barmherzige Brüder Hospital St. Veit/Glan, AustriaDepartment of Surgery, Barmherzige Brüder Hospital St. Veit/Glan, Austria

BACKGROUND

Depth of infiltration of bowel wall is an important prognostic factor in colo-rectal malignancies. Several studies have shown, that the

pT-stage according to UICC/AJCC influences lymph node involvement, vessel invasion, recurrence and long-term survival. However

there is few data about the role of subgroups within pT-stages particularly in pT3-tumors. The aim of our study was to evaluate

whether depth of infiltration within T3 colorectal tumors influences long term oncologic outcome.

MATERIAL AND METHODS

Patients with pT3, N-/+, M0 colon or rectal cancer who

underwent curative (R0) resection at our department between

January 1991 and December 2003 were collected in a

prospectively maintained cancer database. For our analysis

additional pathologic examinations according to TNM

supplement published by Hermanek P. et al in 1993 were

performed and four subgroups, a through d, based on depth of

microscopic penetration into the subserosa were categorized

(Figure 1). The influence on local recurrence and/or distant

metastasis as well as overall and disease-free survival was

tested for each subgroup and compared in an univariate and

multivariate analysis.

Measuring the maximal tumour invasion beyond the outer border of the muscularis propria

pT3a ≤ 1 mm

pT3b > 1-5 mm

pT3c > 5-15 mm

pT3d > 15 mm

pT3 SUBCLASSIFICATION

MucosaMucosa

SubmucosaSubmucosa

M. propriaM. propria

SubserosaSubserosa

SerosaSerosa Figure 1

RESULTS

Overall 368 patients were evaluated with a median age of 69 years (range 32 – 92) and a median follow-up time of 92.5 months

(range 0 – 196). In 181 patients with colon cancer 5- and 10 years overall survival was 82.7% and 65.0%; 5- and 10 years disease

free survival was 80.9% and 64.4%. For 187 rectal cancer patients 5- and 10 years overall survival was 69.0% and 50.5%; 5- and 10

years disease free survival was 61.3% and 47.5%. The survival rates for pT3 subgroups are shown in Figure 2-5.

Neither in colon nor in rectal cancer different pT3 subgroups showed a statistical significant influence on survival or the occurrence of

local or distant recurrence in univariate and multivariate analyses. However there was a significant influence of higher pT3 subgroups

on lymph node involvement and vessel invasion in rectal cancer patients.

CONCLUSIONS

Subdivision of pT3 tumors in colon cancer, based on depth of infiltration does

not provide us with additional information about prognosis.

In rectal cancer T3 – substages were associated with lymph node

involvement, however we could not show an impact on recurrence or survival.

According to our results in patients with T3 colorectal cancer, prognosis or

treatment decisions cannot be based on pathologic substaging by depth of

infiltration.

LITERATURE

1. Hermanek P, Henson DE, Hutter RVP, Sobin LH, eds. International Union Against Cancer (UICC): TNM Supplement 1993. A commentary on uniform use. Berlin, Heidelberg, New York. Springer Verlag; 1993: 122.

Overall Survival Percentages (Colon)

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Survival Time [month]0 10 20 30 40 50 60 70 80 90 100 120 140 160 180

pT class 3A 3B 3C 3D

Overall Survival Percentages (Rectum)

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Survival Time [month]0 10 20 30 40 50 60 70 80 90 100 120 140 160 180

pT class 3A 3B 3C 3D

Disease Free Survival Percentages (Colon)

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Survival Time [month]

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200

pT class 3A 3B 3C 3D

Disease Free Survival Percentages (Rectum)

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100%

Survival Time [month]0 10 20 30 40 50 60 70 80 90 100 120 140 160 180

pT class 3A 3B 3C 3D