Malignant adenomatous neoplasm is cancer that originates in glandular cells that make and release bodily fluids including but not limited to digestive juices and mucus. Because glandular cells are found in tissue that lines internal organs, the condition, which is also referred to as adenocarcinoma, can occur in different parts of the body. These include the lungs, prostate, pancreas, oesophagus, and colon.
Adenocarcinoma accounts for roughly 50% of all lung cancers (adenocarcinoma of lung), 95% of rectal and colon cancers, and 99% of all prostate cancers. A very rare form of the condition is called adenoid cystic carcinoma, which starts in the sinonasal mucosa and spreads to the base of the skull. The benign counterpart of adenocarcinoma is an adenoma. In some cases, adenomas become malignant but most do not.
Although the disease is very common, the exact causes of malignant adenomatous neoplasm remain unknown. However, studies on patients with adenocarcinoma have helped identify factors that can increase one’s risk of developing the disease. These include:
Certain types of infections, including human papillomavirus (HPV), which has been observed in some patients with cervical and uterine cancers
Chronic bowel inflammation
Chronic inflammatory diseases that affect the female reproductive system
Exposure to radiation for the treatment of other types of cancers
A family history of adenocarcinoma
Metabolic diseases such as diabetes and obesity
Old age or weakened immune system
Unhealthy lifestyle habits – Physical inactivity coupled with a diet high in fats has been found to increase the risk of gastric adenocarcinoma.
Alcohol and drug abuse
Gastroesophageal reflux disease (GERD) and Barrett’s oesophagus – Increase the risk of esophageal cancer
Inherited gene mutations – These include familial adenomatous polyposis that can increase the risk of colon cancer.
It is important to note that having risk factors does not automatically mean that a patient will develop malignant adenomatous neoplasm. In fact, many individuals have these factors and have remained cancer-free throughout their lives. However, some patients develop the condition despite not having any risk factors.
The symptoms of adenocarcinoma cancer vary depending on the location of the malignant tumour.
Lung adenocarcinoma - Chest pain, a cough that progressively gets worse, pneumonia, and bronchitis
Gastric adenocarcinoma - Abdominal pain, indigestion, anaemia, and fluid build-up in the abdomen
Adenocarcinoma of the uterus - Uterine bleeding not associated with menstruation and endometrial polyps
Rectal adenocarcinoma - Pain in the lower abdominal area, bloating, chronic constipation, unexplained weight loss, and mucus or blood in foeces
Metastatic adenocarcinoma - Cancer cells that have spread to different parts of the body produce other symptoms, which vary depending on the metastatic site. These include:
Fractures, when cancer spreads to the bone
Breathing problems, when cancer spreads to the lungs
Swollen abdomen, when cancer spreads to the liver
Seizures, when cancer spreads to the brain
Patients suffering from symptoms mentioned above must consult their family physician or a general practitioner for an initial assessment. If preliminary medical exams suggest the presence of cancer, the patient will be referred to oncologists that specialise in the diagnosis, treatment, and management of the disease (e.g., gynaecologic oncologist for uterine cancer and pulmonary oncologist for lung cancer).
Various diagnostic tests are performed to confirm adenocarcinoma diagnosis and to rule out other medical conditions that produce similar symptoms. These tests include:
Biopsy - The removal of a small tissue sample from the tumour. The procedure can be performed percutaneously or through traditional open biopsy. The goal is to obtain and study a small amount of tissue sample under a microscope to ascertain the presence of cancer cells.
Computed tomography (CT) scan - An imaging procedure that produces 3D pictures of different parts of the body, allowing doctors to easily spot abnormalities. CT scans are also performed during and after treatment to measure the effectiveness of therapies and check for recurrence.
Magnetic resonance imaging (MRI) - Just like CT scans, MRI scanning also produces detailed images of different parts of the body to easily spot abnormalities. It uses radiofrequency waves to create cross-sectional pictures of the affected site.
Adenocarcinoma treatment is largely dependent on these factors: the location of the malignant tumour, the stage of cancer, the patient’s overall health condition, and the patient’s preferences. However, standard treatment combines surgery and adjuvant therapies.
Surgery - In the majority of cases, patients undergo surgery for the removal of cancerous glandular tissue along with a wide margin of surrounding tissue. Small tumours can now be removed using minimally surgical methods that use small incisions instead of one long surgical cut. This is widely preferred by both doctors and patients because it significantly minimises postsurgical complications and shortens hospital stay.
Chemotherapy - Refers to the use of drugs that kill cancer cells that have spread to other parts of the body. It can also be recommended before surgery to shrink the tumour.
Radiation therapy - This cancer treatment uses gamma rays, protons or electron beams to damage cancer cells. Radiation keeps cancer cells from growing and dividing to stop the condition from progressing. Unlike chemotherapy, radiation therapy is more focused and is likely to spare healthy cells during the treatment process.
Adenocarcinoma survival rate is determined by the stage of cancer. For patients with adenocarcinoma lung cancer, for example, the five-year survival rate is:
55% for stage I
49% for stage IIA
35% for stage IIB
31% for stage IIIA
18% for stage IIIB
5% for stage IV
The stage of cancer is based on the extent of the tumour and whether cancer cells have spread to the lymph nodes and distant body parts. Stage 1 refers to localised tumour while advanced stages are characterised by the spread of cancer cells to various organs.
Chapter 13, box on morphology of adenocarcinoma in: Mitchell, Richard Sheppard; Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson. Robbins Basic Pathology. Philadelphia: Saunders. ISBN 1-4160-2973-7. 8th edition.
Distress management. Fort Washington, Pa.: National Comprehensive Cancer Network. http://www.nccn.org/professionals/physiciangls/fguidelines.asp.
Colon cancer treatment (PDQ). National Cancer Institute. http://www.cancer.gov/types/colorectal/patient/colon-treatment-pdq.