Relationship of Cancer Type and Symptoms

This article discusses how different types of cancer are related to specific symptoms.    This article will review the three most common cancers (i.e. Breast, Colon and Lung) and explain in very basic terms how these symptoms are related to each cancer.

In order to fully appreciate how certain symptoms point to a specific cancer location it is necessary to introduce a few basic concepts of human anatomy and physiology.  An important general principle of understanding the anatomy and functioning of the human body is to realize that FORM FOLLOWS FUNCTION.  The arrangement of proteins such as actin and myosin seem to be arranged like the planks of a bridge or the interlocking parts from a machine with many gears.  When viewed under a microscope, these key parts of muscle seem to suggest their function.  Movement of the arm requires flexion of a muscle which is really just shortening of the carefully arranged actin and myosin filaments.  In a similar way, the carefully arranged tubes and filtering apparatus that is seen within the nephron seems to suggest the function of the kidneys.  When viewed under the microscope, the functional unit of the kidney is seen to have long tubes that carry fluid and at the same time filter this fluid and dilute or concentrate it as needed.  The arrangement and form of these essential bodily elements helps give an understanding of its function.

A similar understanding must be had in order to interpret the relationship between symptoms from a cancer and the type of cancer.  In order to do this, a basic understanding of the components of the body and the function of different bodily organs is required.  This article will review the three most common cancers (i.e. Breast, Colon and Lung) and explain in very basic terms how these symptoms are related to each cancer.

Breast Cancer: The breast can be thought of as a bunch of grapes complete with a stem and many grapes on each dividing branch.  The breast is composed of lobules and is connected by ducts that continue to connect to a central duct system that drains via the nipple.  The grapes are analogous to the breast lobules and the grape stem is analogous to the ductal system within the breast.  Most breast cancers arise from either the breast lobule or the breast ducts, although there are several other types.  The breast tumors are named for these reasons such as invasive ductal carcinoma, ductal carcinoma in-situ, invasive lobular carcinoma, or the marker known as lobular carcinoma in-situ.  Symptoms of breast cancer thus relate to the function and form of the breast.  Common symptoms of the breast include:

  • nipple discharge
  • a new lump felt
  • rash of the nipple or breast
  • pain in the breast

Nipple discharge may be spontaneous (occurring without any nipple or breast stimulation) or induced (i.e. it only occurs when the breast is massaged or nipple pinched).  The nipple discharge might be clear, milky, green, foul-smelling, or bloody.  The lump felt may seem to come and go over the course of a month or it may be felt to grow over the course of many months.  All of these different symptoms relate to basic functions of the breast and can be understood by considering the normal physiology of the breast.  The female breast reacts to hormone changes that occur with a normal menstrual cycle, with pregnancy and when taking a hormone medication.

Estrogen, the main female hormone responsible for feminizing traits, causes breast tissue to enlarge and develop.  It is not uncommon for breast size or density to change slightly during a menstrual cycle or enlarge during pregnancy as more of these hormones are produced.  Nipple discharge occurs from secretions in the breast gland (lobules) or the ducts.  Most nipple discharge is normal clear fluid produced by the breast glands that can be increased during pregnancy or with nipple stimulation.  Bloody discharge or blood tinged discharge is often concerning but is usually from a non-cancerous growth within the duct system.  Many symptoms that might occur with breast cancer are also common normal occurrences as well making interpretation of these symptoms difficult.  Certainly a new found breast lump is concerning and should be brought to the attention of a physician for further evaluation.  Just as breast tissue can grow throughout a normal cycle, so can a breast cancer grow sometimes under influence of the same hormones such as estrogen.

Colon Cancer:  In order to understand the symptoms of colon cancer the basic anatomy and function of the colon must be briefly reviewed.  The colon is a collecting and concentrating reservoir at the end of the gastrointestinal tract.  The colon performs several key jobs:

  • Absorption of water
  • Fermentation
  • Store wastes
  • Absorb electrolytes
  • Vitamin K production

The colon allows storage and periodic release of stool in a socially acceptable way.  The majority of stool is not “old food” but bacteria, thus the colon is the “dirtiest” place in the body with a bacteria count of approximately 1014.  The lining of the colon is supplied by several sources of blood and is optimized to allow a big surface area through many folds.  A cancer that grows in the colon will cause disruption of these functions thus explaining many of the common symptoms.  Common symptoms of colon cancer include:

  • Passage of blood with stool
  • Nausea or Vomiting
  • Weight Loss
  • Swelling of the abdomen
  • Fatigue

Blood found in the stool may either be bright red, old and clotted, or microscopic and only detectable with special testing.  Bleeding is very common with colon tumors because the tumor tend to grow through the lining of colon and by doing so disrupt the very rich blood supply and cause bleeding.  With blood loss over time, low blood counts (also known as anemia) will develop.  Anemia can be directly responsible for fatigue and weight loss as well.  If the passage of wastes and stool through the colon is partially blocked or completely blocked, discomfort in the stomach, swelling, and nausea with vomiting will develop.  All of these intestinal complaints will be more common with a larger tumor as the passageway gets progressively smaller and smaller.  Pain may occur as a tumor low in the colon or rectum begins to grow into pelvic nerves.  Pain with colon cancer is often a sign of advanced cancer.

Lung Cancer:  A brief review of normal lung anatomy and function is needed to understand how lung cancer symptoms may be related to lung cancer.  The lungs can be imagined as a tree with about 23 generations or branch points.  The branches organize themselves into 20 segments or groupings.  The 20 segments are divided between 5 lobes – three on the right and two and the left.  Most cartoon drawings of the lung depict two sacs or balloon like structures on each side of the chest.  The key feature of the lung is that its form is optimized for creating maximal surface area.  It is estimated that the surface area of the lung is about the size of a tennis court.  This surface area is needed to allow maximal room for gas exchange.

We breathe in air that contains mostly nitrogen and about 20% oxygen.  Our lungs only have a fraction of a second to allow transfer of this oxygen into the blood and transfer of carbon dioxide out of the lung.  The movement of air in and out of the lungs has been compared to the tides of the ocean.  This is why the air that is moved in and out with a breathing cycle is referred to as a tidal volume.

The airways have a rich blood and nerve supply.  A powerful cough reflex happens when even the smallest fiber or foreign body enters the airways.

Tumors in the lung can be of several different cell types but they all interfere with normal lung function in some way thus being responsible for the main symptoms of lung cancer.  Common symptoms of lung cancer include:

  • Cough (either a dry cough, or with mucus, or possibly blood)
  • Chest pressure
  • Chest pain
  • Shortness of breath
  • Wheezing
  • Weakness & Fatigue
  • Weight loss

As a lung tumor grows, depending on the location within the lung, it can block the flow of air to areas of the lung downstream.  For example, a tumor growing in the 2nd or 3rd branching of the lung will cause blockage or restricted air flow to the lung on that side.  Several problems will result from this.  The person with this tumor will have symptoms of shortness of breath, cough, and possibly fever with foul mucus production.

Difficulty moving air in and out of the lungs creates a serious anxiety with breathing called dyspnea or shortness of breath.  It may require more effort of the chest muscles to move the same amount of air in and out.  This extra effort will cause fatigue and weight loss.  Fatigue can arise from many factors with lung cancer including hormones made by the tumor, extra breathing effort, and higher metabolism of the tumor, anemia and infections.  Blockage of an airway by a tumor can allow mucus or bacteria to collect downstream from it.  When bacteria grow in the lung it can create an infection known as a pneumonia or abscess.  Sometimes an early sign of lung cancer is a pneumonia that does not seem to get better with usual antibiotic treatment.  All of these anatomic relationships to normal lung function allow a basic understanding of the symptoms of lung cancer.

REFERENCES:

  1. Diagnosing cancer in the symptomatic patient. Salzman BE, Lamb K, Olszewski RF, Tully A, Studdiford J. Prim Care. 2009 Dec;36(4):651-70; table of contents. Review. PMID:  19913180
  2. Abeloff, M.D. (2008). Abeloff: Abeloff’s Clinical  Oncology, 4th ed. Chapter 10.Philadelphia,PA: Churchill Livingstone – Elsevier
  3. www.cancer.gov/cancertopics/factsheet/Sites-Types/metastatic
  4. This article was originally published on September 3, 2012 and last revision and update was 9/4/2015.