Classification

The American Joint Commission on Cancer bases the classification of rectal cancer on the extent of local and/or distant spread (Table 98-1) (Greene et al, 2002). Preoperative staging is used to direct treatment of rectal cancer.

Distant Spread

A chest radiograph is performed routinely and any suspicious abnormalities should be evaluated preoperatively

TABLE 98-1. TNM Staging of Colorectal Carcinoma

Tumor State (T)

Definition

TX

Cannot be assessed

T0

No evidence of cancer

Tis

Carcinoma in situ

T1

Tumor invades submucosa

T2

Tumor invades muscularis propria

T3

Tumor invades through muscularis propria into

subserosa or into nonperitonealized pericolic or

perirectal tissues

T4

Tumor directly invades other organs or tissues or

perforates the visceral peritoneum of specimen

Nodal Stage (N)

Definition

NX

Regional lymph nodes cannot be assessed

N0

No lymph node metastasis

N1

Metastasis to one to three pericolic or perirectal

lymph nodes

N2

Metastasis to four or more pericolic or perirectal

lymph nodes

N3

Metastasis to any lymph node along a major named

vascular trunk

Distant Metastasis (M)

Definition

MX

Presence of distant metastasis cannot be assessed

M0

No distant metastasis

M1

Distant metastasis present

with a computed tomography (CT) scan of the chest. A CT scan of the abdomen and pelvis is also routine, both to rule out the presence of liver metastases and to evaluate the relationship between the rectal tumor and contiguous structures. Positron emission tomography (PET) scanning is not routinely recommended for preoperative evaluation but may be useful in select patients, for example in patients with locally advanced disease who are at high risk of occult metastases or in the examination of patients with equivocal lesions on chest or abdominal CT.

Local Staging

Accurate local staging to determine invasion through the rectal wall and the presence or absence of lymph node metastasis guides selection of appropriate therapy. For early stage disease, local therapy may be appropriate, whereas for advanced rectal cancer, neoadjuvant chemoradiation may be indicated. Imaging with endorectal ultrasound (US) or magnetic resonance imaging (MRI) is recommended for preoperative staging. Endo-anal coils may increase the accuracy of MRI. Sensitivity and specificity for depth of invasion are highest for endorectal US, 93% and 78% respectively, although endo-anal coil MRI approaches these values (Kwok et al, 2000). Endorectal US accurately distinguishes T2 from T3 cancers but is less accurate at differentiating T1 from T2 cancers. Endorectal US is less accurate than MRI in the determination of lymph node involvement, with sensitivity and specificity of 71% and 76% versus 82% and 83%, respectively. CT scanning does not have adequate sensitivity or specificity to accurately direct choice of therapy protocol.

Constipation Prescription

Constipation Prescription

Did you ever think feeling angry and irritable could be a symptom of constipation? A horrible fullness and pressing sharp pains against the bladders can’t help but affect your mood. Sometimes you just want everyone to leave you alone and sleep to escape the pain. It is virtually impossible to be constipated and keep a sunny disposition. Follow the steps in this guide to alleviate constipation and lead a happier healthy life.

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