Oesophageal cancer

Types of Oesophageal Cancer

There are two types of cancer of the oesophagus; Oesophageal Squamous Cell Carcinoma (OSCC) and Oesophageal Adenocarcinoma (OAC).

Squamous Cell Carcinomas are more prevalent in Asian countries whilst Oesophagel Adenocarcinomas are more prevalent in UK, Europe and America.

SCC is more likely to be found in the upper oesophagus and is heavily linked to drinking and smoking. Rates of SCC are remaining static.

OAC is more likely to be found in the lower oesophagus and is heavily linked to acid reflux and Barrett's Oesophagus. Rates of OAC are rising rapidly.

In UK, OAC is the 13th most commonly identified cancer, more common in men in whom it's the 8th most common cancer.

Deaths from oesophageal cancer in UK, however, are disproportionately higher with it being the fourth most common cancer killer amongst men and 7th amongst women accounting for one person an hour on average with mortality rates having increased by 65% in the last 40 years.

Treatment for Oesophageal cancer depends upon its stage at discovery.

Cancers are staged using TNM codes as described below.

T refers to the stage of the primary Tumour, N refers to Lymph Nodes and M to metastasis (ie whether it's spread to other organs).

How Can Barrett's mutate to  Cancer?

The following comes from Barrett's Esophagus Info (previously a website provided by the Ryan Hill Research Foundation until 2008 when its funding was withdrawn).

The normal cell cycle

In most tissues of the body, cells multiply through a process known as the cell cycle. Before cells can multiply and divide into other cells, they have to make exact copies of their DNA. DNA is the genetic code that is in all the cells of our bodies and is exactly the same code in each cell no matter what tissue the cell is from.

Chromosomes are made up of the genes of our cells and our genes are made up of strands of DNA. Each cell of our body has two copies of each gene, one inherited from our mother and one from our father. The nucleus of the cell houses our chromosomes and genes.

Normally, most cells are not actively growing and dividing and are in the G0 or resting phase of the cell cycle and have a diploid or 2N DNA content. Cells in the G1 phase are actively cycling but like G0 cells have a "diploid" or 2N DNA content. A small percentage of cells in normal tissues are undergoing DNA synthesis (making a copy of their DNA) and are in the S phase of the cell cycle (have a DNA content between 2N and 4N). A few cells have completed their DNA synthesis and doubled their amount of DNA and are in the G2 phase of the cell cycle (have a 4N or tetraploid DNA content). After cells double their DNA, they undergo mitosis (M phase) dividing into two daughter cells that are exact genetic copies of each other and have a DNA content of 2N.

Nowell's hypothesis

There are many events or steps that occur in Barrett's esophagus that lead to the development of cancer. A few of these events are known but most are not. Most of the known events appear to occur early, before high-grade dysplasia or cancer actually develops. No one knows what the late events are that give cells the ability to leave their normal growth boundaries and become a cancer.

It is now widely accepted that the development of most cancers is due to something called genomic or genetic instability. This theory was first proposed by Dr. Peter Nowell in 1976. The theory is that for some unknown reason, perhaps due to environmental factors or inherited factors, some cells in the body develop genetic abnormalities that give them the ability to outgrow genetically normal cells. These abnormal cells grow and expand into a clone of cells (a group of cells having the same genetic make-up) and may replace their neighboring normal cells. Eventually one of the abnormal clones may undergo another genetic change that leads to the development of a sub-clonal population with the expansion of this cell line into its own large clone of cells.

As multiple genetic abnormalities occur, multiple sub-clones develop or evolve. Eventually, one of these sub-clones may acquire the necessary combination of genetic abnormalities to become a cancer.

Ball Diagram of Nowell's Hypothesis

The green balls represent cells that have developed a genetic abnormality and are expanding or growing into a clone of cells.
One of these cells develops a second genetic abnormaility, illustrated by a blue ball, seen to expand into its own clone of cells or subclones of the green population.
A third genetic mistake is made, illustrated by a dark red ball, with clonal exansion of this cell population.

Eventually, another genetic mistake is made in one of the cells of the dark red population that allows that cell to become a cancer.

Survival for oesophageal cancer

From Cancer Reasearch UK. (N.B. These statsistics combine OSCC and OAC):

Stage 1

Almost 55 out of 100 people (almost 55%) with stage 1 oesophageal cancer will survive their cancer for 5 years or more after they're diagnosed. 

Stage 2
30 out of 100 people (30%) with stage 2 oesophageal cancer will survive their cancer for 5 years or more after they're diagnosed. 

Stage 3
Around 15 out of 100 people (around 15%) with stage 3 oesophageal cancer will survive their cancer for 5 years or more after they're diagnosed. 

Stage 4
There are no 5 year survival statistics for stage 4 cancer because sadly many people don't live for that long after diagnosis.

Footnote from Barrett's UK:

Barrett's surveillance aims to find mutation before it reaches stage 1 when it can be stopped in its tracks.

Barrett's can be managed; Cancer can kill!

Find Barrett's before it can become cancer.

Page update 17 March 2024