Oncology – interactive session 1
Question A. What is the aim of the screening program?
The aim of a bowel cancer screening program is to detect colorectal cancer (commonly referred to as bowel cancer)
at an early and more treatable stage or to identify precancerous lesions (such as polyps) that can be removed before
they develop into cancer. Early detection and intervention can significantly improve the chances of successful
treatment and reduce mortality rates associated with colorectal cancer.
Bowel cancer screening programs typically involve the use of specific tests to detect abnormalities in the colon or
rectum. These tests can include fecal occult blood tests (FOBT), fecal immunochemical tests (FIT), and colonoscopies.
Question B. There are several reasons why it is becoming increasingly important to focus on cancer
prevention. Mention a reason.
• Epidemiological Trends: The global incidence of cancer has been rising, and cancer is a leading cause of
morbidity and mortality worldwide. As populations age and lifestyle factors change, the burden of cancer is
expected to increase. Prevention efforts become crucial in addressing this growing public health challenge.
• Cost-Effectiveness: Treating cancer can be expensive, both for individuals and healthcare systems. Prevention
strategies, such as vaccination against certain cancers (e.g., HPV vaccination for cervical cancer prevention) or
lifestyle modifications, can be cost-effective in the long run by reducing the need for extensive and costly
cancer treatments.
• Advancements in Knowledge: Scientific research has provided a deeper understanding of the genetic,
environmental, and lifestyle factors that contribute to cancer development. This knowledge enables the
identification of specific risk factors and the development of targeted prevention strategies.
• Quality of Life: Preventing cancer not only saves lives but also contributes to better overall health and well-
being. Many cancer prevention strategies, such as vaccination and healthy lifestyle choices, have positive
impacts on general health, reducing the risk of other chronic conditions.
Question C. Different cancers have different risk factors. Name one risk factor for colorectal cancer that can be
changed and one that cannot.
One modifiable risk factor for colorectal cancer is diet. Dietary choices, such as consuming a diet high in red and
processed meats, low in fiber, and lacking in fruits and vegetables, have been associated with an increased risk of
colorectal cancer. Making positive changes in diet, such as increasing fiber intake and reducing the consumption of
processed and red meats, can potentially lower the risk of colorectal cancer.
One non-modifiable risk factor for colorectal cancer is aging. The risk of developing colorectal cancer increases with
age, and most cases are diagnosed in individuals over the age of 50. While age is not something that can be changed,
routine screenings, such as colonoscopies, are recommended for individuals in certain age groups to detect and
prevent colorectal cancer at an early and more treatable stage. However, certain genetic mutations, such as mutations
in the adenomatous polyposis coli (APC) gene, can contribute to the development of colorectal cancer. In familial
adenomatous polyposis (FAP), individuals inherit a mutated APC gene, leading to the formation of numerous polyps
in the colon and a significantly increased risk of developing colorectal cancer at a young age.
Question D. What kind of human observational studies are needed to give convincing evidence that
a lifestyle factor increases the risk of developing cancer?
To establish convincing evidence that a lifestyle factor increases the risk of developing cancer, researchers often rely
on well-designed human observational studies. These studies aim to observe and analyze the relationship between
specific lifestyle factors and the incidence of cancer in human populations. Examples of studies are:
• Cohort Studies: follow a group of individuals over time, collecting information on their lifestyle factors,
behaviors, and health outcomes, including cancer incidence. However, this study is time-consuming and
expensive and there are ethical concerns
o If the exposure under investigation is known to be harmful, researchers may be reluctant to expose a
group of participants to that risk.
, • Case-Control Studies: compare individuals with a specific cancer (cases) to those without the cancer (controls)
and assess their past exposures and lifestyle factors. However, this study is retrospective, meaning that they
rely on the recall of past events or exposures by participants. This introduces the potential for recall bias,
where cases may be more likely to remember or report exposures of interest compared to controls.
Question E. Processed meat is classified as carcinogenic to humans. In the processed meat, nitrosamines are
recognized as important carcinogenic compounds. In which two major groups are carcinogens divided in current
regulations? And to which group do the nitrosamines belong?
Carcinogens are generally classified into two major groups in current regulations:
• Genotoxic carcinogens: These are substances that directly interact with genetic material (DNA) and can cause
mutations. Genotoxic carcinogens are often associated with a higher risk of cancer development. Examples
include certain chemicals, radiation, and some types of viruses.
• Non-genotoxic carcinogens: These carcinogens do not directly interact with DNA but instead promote cancer
development through other mechanisms, such as promoting cell proliferation or inhibiting cell death.
Examples include hormones and certain chemicals.
Nitrosamines, including those found in processed meat, are genotoxic carcinogens. They are formed when
nitrites and amines present in certain foods react under certain conditions, such as during the processing or
cooking of meat. Nitrosamines have been linked to an increased risk of cancer, particularly in the digestive
system
Question F. What are signs of dysplasia?
Dysplasia refers to the abnormal development or growth of cells within a tissue. It is often considered a precancerous
condition, as it may precede the development of cancer. The signs of dysplasia can vary depending on the specific
tissue or organ affected. Here are some general signs and characteristics associated with dysplasia:
• Changes in Cell Appearance: Under a microscope, cells affected by dysplasia often show abnormal features in
terms of size, shape, and organization. These changes can be observed in tissue samples obtained through
biopsy.
• Increased Cell Proliferation: Dysplasia is characterized by an increased rate of cell division, leading to an
overgrowth of cells in the affected tissue.
• Loss of Normal Tissue Architecture: The normal tissue structure may be disrupted as a result of dysplasia. The
cells may no longer be arranged in a well-organized manner.
• Altered Nuclear Characteristics: The nuclei of cells in dysplastic tissue often exhibit abnormalities, such as
changes in size, shape, and staining patterns.
• Increased Nuclear-Cytoplasmic Ratio: Dysplastic cells may have a higher ratio of nucleus to cytoplasm
compared to normal cells. This is a common feature observed microscopically.
• Presence of Mitotic Figures: Increased mitotic activity, evidenced by the presence of mitotic figures (cells
undergoing division), is often seen in dysplastic tissue.
Question G. What does TNM staging (pT3N0M0) describe and how is it used?
The TNM staging system is a widely used system for describing the extent of cancer based on three key pieces of
information: T (tumor size and extent), N (lymph node involvement), and M (presence or absence of distant
metastasis). Each of these categories is assigned a numerical value, and the combination provides a detailed
description of the cancer stage. Let's break down the components of the TNM staging system:
• T (Tumor)
o pT3 indicates the primary tumor's size and extent. The "p" stands for pathologic, meaning it is
determined based on examination of the surgical specimen rather than clinical assessments.
o T3 typically signifies a larger or more invasive primary tumor. The exact criteria for T3 staging can vary
depending on the type of cancer.
• N (Nodes)
o N0 indicates the absence of regional lymph node involvement.
o The presence of lymph node involvement is denoted by higher numbers (e.g., N1, N2, N3), with
increasing numbers indicating greater extent or number of affected lymph nodes.
, • M (Metastasis)
o M0 signifies no distant metastasis, indicating that the cancer has not spread to distant organs or
tissues.
o M1 would indicate the presence of distant metastasis, suggesting that the cancer has spread to other
parts of the body beyond the primary site and regional lymph nodes.
So, in the case of pT3N0M0:
• The primary tumor (T) is classified as pathologic T3, suggesting a more advanced or larger primary tumor.
• There is no regional lymph node involvement (N0).
• There is no evidence of distant metastasis (M0).
Question H. What type of treatment is surgery (local/systemic) and what is in this case the goal of this treatment
(curative/palliative)?
Surgery is a local treatment for cancer, as it involves the removal of the tumor and surrounding tissues directly at the
site of the primary cancer. The goal of surgery can be either curative or palliative, depending on the specific
circumstances of the cancer and the patient's overall health.
Curative Surgery:
• The primary goal of curative surgery is to remove the entire tumor along with any nearby tissues that may
harbor cancer cells. This is often the case when the cancer is localized and has not spread beyond the primary
site.
• Curative surgery aims to achieve a complete cure, eliminating the cancer and preventing its recurrence.
Palliative Surgery:
• Palliative surgery is performed to relieve symptoms or improve the quality of life for individuals with advanced
or metastatic cancer.
• The primary goal is not to cure the cancer but to alleviate pain, obstruction, bleeding, or other symptoms
caused by the tumor. Palliative surgery may involve removing part of the tumor or debulking it to reduce its
size and improve symptoms.
Question I. Why is the information on invasion relevant?
The information on invasion, specifically vascular, lymphatic, and perineural invasion, is crucial in the pathology report
because it provides important insights into the behavior of the tumor and its potential to spread. By understanding
the invasion characteristics of a tumor, the oncologists can …
• Determine the stage of the cancer, which guides treatment decisions.
• Assess the risk of local recurrence and distant metastasis.
• Develop a personalized treatment plan that may include surgery, radiation therapy, chemotherapy, or other
targeted therapies.
• Provide more accurate prognostic information to the patient.
In summary, invasion characteristics play a crucial role in assessing the aggressiveness of the tumor, predicting
its potential to spread, and tailoring appropriate treatment strategies to address the specific features of the
cancer.
Vascular Invasion:
• Vascular invasion refers to the presence of cancer cells within blood vessels. If cancer cells invade blood
vessels, it indicates the potential for the tumor to spread to other parts of the body through the bloodstream,
a process known as hematogenous metastasis.
• Detection of vascular invasion is important for staging and treatment planning. It may influence decisions
about the need for additional therapies, such as chemotherapy or targeted therapy, to address the risk of
distant metastasis.
Lymphatic Invasion:
