Location and appearance of two example colorectal tumors
Cancers and tumors are caused by a series of mutations. Each mutation alters the behavior of the cell somewhat.
Longitudinally opened freshly resected colon segment showing a cancer and four polyps. Plus a schematic diagram indicating a likely field defect (a region of tissue that precedes and predisposes to the development of cancer) in this colon segment. The diagram indicates sub-clones and sub-sub-clones that were precursors to the tumors.
The central role of DNA damage and epigenetic defects in DNA repair genes in carcinogenesis
Colon cancer with extensive metastases to the liver
Longitudinally opened freshly resected colon segment showing a cancer and four polyps. Plus a schematic diagram indicating a likely field defect (a region of tissue that precedes and predisposes to the development of cancer) in this colon segment. The diagram indicates sub-clones and sub-sub-clones that were precursors to the tumors.
Relative incidence of various histopathological types of colorectal cancer. The vast majority of colorectal cancers are adenocarcinomas.
Tissue can be organized in a continuous spectrum from normal to cancer.
Micrograph of colorectal adenocarcinoma, showing "dirty necrosis".
Many tumor suppressor genes effect signal transduction pathways that regulate apoptosis, also known as "programmed cell death".
A diagram of a local resection of early stage colon cancer
Multiple mutations in cancer cells
A diagram of local surgery for rectal cancer
Colon and rectum cancer deaths per million persons in 2012

As summarized in the articles Carcinogenesis and Neoplasm, for sporadic cancers in general, a deficiency in DNA repair is occasionally due to a mutation in a DNA repair gene, but is much more frequently due to epigenetic alterations that reduce or silence expression of DNA repair genes.

- Colorectal cancer

Adenopolyposis colon cancer is associated with thousands of polyps in colon while young, leading to colon cancer at a relatively early age.

- Carcinogenesis
Location and appearance of two example colorectal tumors

4 related topics with Alpha

Overall

A coronal CT scan showing a malignant mesothelioma
Legend: → tumor ←, ✱ central pleural effusion, 1 & 3 lungs, 2 spine, 4 ribs, 5 aorta, 6 spleen, 7 & 8 kidneys, 9 liver

Cancer

3 links

Group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body.

Group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body.

A coronal CT scan showing a malignant mesothelioma
Legend: → tumor ←, ✱ central pleural effusion, 1 & 3 lungs, 2 spine, 4 ribs, 5 aorta, 6 spleen, 7 & 8 kidneys, 9 liver
Symptoms of cancer metastasis depend on the location of the tumor.
The GHS Hazard pictogram for carcinogenic substances
Share of cancer deaths attributed to tobacco in 2016.
The incidence of lung cancer is highly correlated with smoking.
Cancers are caused by a series of mutations. Each mutation alters the behavior of the cell somewhat.
The central role of DNA damage and epigenetic defects in DNA repair genes in carcinogenesis
Chest X-ray showing lung cancer in the left lung
Three measures of global cancer mortality from 1990 to 2017
Engraving with two views of a Dutch woman who had a tumor removed from her neck in 1689
University of Florida Cancer Hospital
CancerTreeMammal
An invasive ductal carcinoma of the breast (pale area at the center) surrounded by spikes of whitish scar tissue and yellow fatty tissue
An invasive colorectal carcinoma (top center) in a colectomy specimen
A squamous-cell carcinoma (the whitish tumor) near the bronchi in a lung specimen
A large invasive ductal carcinoma in a mastectomy specimen

Early detection through screening is useful for cervical and colorectal cancer.

Several studies have indicated that the enzyme sirtuin 6 is selectively inactivated during oncogenesis in a variety of tumor types by inducing glycolysis.

Illustration showing hematogenous metastasis

Metastasis

1 links

Pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor.

Pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor.

Illustration showing hematogenous metastasis
Cut surface of a liver showing multiple paler metastatic nodules originating from pancreatic cancer
Lymph node with almost complete replacement by metastatic melanoma. The brown pigment is focal deposition of melanin
Main sites of metastases for some common cancer types. Primary cancers are denoted by "...cancer" and their main metastasis sites are denoted by "...metastases".
Pulmonary metastases shown on Chest X-Ray
Cut surface of a humerus sawn lengthwise, showing a large cancerous metastasis (the whitish tumor between the head and the shaft of the bone)
Micrograph of thyroid cancer (papillary thyroid carcinoma) in a lymph node of the neck. H&E stain
CT image of multiple liver metastases
CT image of a lung metastasis
Metastasis proven by liver biopsy (tumor (adenocarcinoma)—lower two-thirds of image). H&E stain.
Metastatic cancer in the lungs
Metastases from the lungs to the brain
Metastases from the lungs to the pancreas

This malignancy allows for invasion into the circulation, followed by invasion to a second site for tumorigenesis.

For example, colorectal cancer spreads primarily through the portal vein to the liver.

Endoscopic image of sigmoid colon of patient with familial adenomatous polyposis

Familial adenomatous polyposis

1 links

Autosomal dominant inherited condition in which numerous adenomatous polyps form mainly in the epithelium of the large intestine.

Autosomal dominant inherited condition in which numerous adenomatous polyps form mainly in the epithelium of the large intestine.

Endoscopic image of sigmoid colon of patient with familial adenomatous polyposis
CHRPE - Congenital hypertrophy of the retinal pigment epithelium
Micrograph of a tubular adenoma, the colorectal cancer precursor most commonly associated with FAP
Colectomy specimen showing numerous polyps throughout the large bowel

While these polyps start out benign, malignant transformation into colon cancer occurs when they are left untreated.

(APC regulates β-catenin, a protein that plays a crucial role in cell communication, signalling, growth, and controlled destruction, but which left uncontrolled also gives rise to numerous cancers ).

CT scan of a liver with cholangiocarcinoma

Liver cancer

1 links

Cancer that starts in the liver.

Cancer that starts in the liver.

CT scan of a liver with cholangiocarcinoma
Liver tumor types by relative incidence in adults in the United States (liver cancers in dark red color).
This electron micrograph shows hepatitis B virus "Dane particles", or virions.
High magnification micrograph of a liver with cirrhosis. Trichrome stain. The most common cause of cirrhosis in the Western world is alcohol use disorder – the cause of cirrhosis in this case.
Left lobe liver tumor in a 50-year-old male, operated in King Saud Medical Complex, Riyadh, Saudi Arabia
A surgeon performing photodynamic therapy
Deaths from liver cancer per million persons in 2012

Frequently, the site of origin is the gastrointestinal tract, since the liver is close to many of these metabolically active, blood-rich organs near to blood vessels and lymph nodes (such as pancreatic cancer, stomach cancer, colon cancer and carcinoid tumors mainly of the appendix), but also from breast cancer, ovarian cancer, lung cancer, renal cancer, prostate cancer.

Mutation in p53, presumably in conjunction with other aflatoxin-induced mutations and epigenetic alterations, is likely a common cause of aflatoxin-induced carcinogenesis.