This is important questions for Biology Makaut semester examination

1. A What is cancer?
Answer:
Cancer 1s a genericterm for alarge group of diseases that can affect any part of the body.
Other terms used are malignant tumours and neoplasms.One defining feature ofcancer is
the rapid creation of abnormalcells that grow beyond their usual boundaries,and which
can then invade adjoining parts ofthe body and spread to other organs, the latter process
isreferred to as metastasS1ZIng. Metastases are a maior cause of death from cancer.
Whatare the common cancers?
Answer:
Lung (2.09 million cases)
Breast (2.09 million cases)
Cancer is a leading cause of death worldwide. accounting for an estimated 9.6 million
deaths in 2018. The most common cancers are:
Colorectal (1.80 million cases)
[MODEL QUESTION]
Prostate (1.28 million cases)
Skin cancer (non-melanioma) (1.04 million cases)
Stomach (1.03 million cases)
MODEL QUESTION]

2. 6. Describe howgenescontribute to the risk and growth of cancer.
Answer:
GeneticChanges and Cancer
[MODEL QUESTIONJ
Cancer is a genetic diseasethat is, cancer is caused by certain changes to genes that
control the way our cells function, especially how they grow and divide.
Genes carry the instructions to make proteins, which do much of the work in our cells.
Certain gene changes can cause cells to.evade normal growth controls and become
cancer. For example, some cancer-causing gene changes increase production of a protein
that rmakes cells grow. Others result in theproduction ofa misshapen, and therefore non
functional, form ofa protein that normally repairs cellular damage.
Geneticchanges that promote cancer can be inherited from our parents ifthe changes are
present in gern cells, which are the reproductive cells of thebody (eggs and sperm).
Such changes, called germline changes, are found in every cell oftheoffspring.
Cancer-causing genetic changes can also be acquired during one's lifetime,as the result
of errors that occur as cells divide or from exposure to carcinogenic substances that
damage DNA, such as certain chemicals in tobacco smoke, and radiation, such as
ultraviolet rays from the sun. Genetic changes that occur after conception are called
somatic (or acquired) changes.
There are many differentkinds of DNA changes. Some changes affect just one unit of
DNA, Called anucleotide. One nucleotide may be replaced by another, or it may be
missing entirely. Other changes involve larger stretches of DNA and may include
rearrangements, deletions, or duplicationsof long stretches of DNA.

3. Sometimes the changes are
or removal of chemical
are not in the actualsequence ofDNA. For example, the addition
DNA can
influence whether the
Cnemical marks, called epigenetic modifications, on
al, Cancer cells have more genetic changes than normalcells. But each person s
Cancer has a unique combination ofgenetic alterations.Some of these changesmay be
the result of cancer. rather than the cause. As thecancer continues to grow, additional
changes will occur. Even within the same tumor, cancer cells may have different genetic
changes.
gene is expressed"that is, whether and how much messenger
hy sPauced. (Messenger RNA inturn is translated to produce the proteins encoded

4. 15.What are the Steps of metastasis?
Answer:
The steps ofmetastasis include:
separation from the primary tumor
[MODEL QUESTION]
invasion through tissues around.the initial lesion and penetration of their
basement membranes
entry into the blood vessels and survival within blood - spread via blood vessels
is called hematogenous spread
entry into lymphatics or peritoneal cavity - spread via lymph channels is called
lymphatic spread
reaching the distant organ like lungs, liver, brain bone etc.
formation of a new lesion along with new blood vessels feeding the tumor
formation of new blood vessels is termed angiogenesis
Allthis while, the cancer cells have toavoid being killed by the body's natural immune
system.

5. 20.What is the Role of Image in cancer treatment?
Answer:
Multiple biomedical imaging techniques are used in all phases of cancer management.
Imaging forms an essential part of cancer clinical protocols and is able to furnish
morphological, structural, metabolic and functional information. Integration with other
diagnostic tools such as in vitro tissue and fluids analysis assists in clinical decision
making. Hybrid imaging techniques are able to supply complementary informationfor
improved staging and therapy planning. Image guided and targeted minimally invasive
therapy has the promiseto improve outcome and reduce collateral effects. Early detection
of cancer through screening based on imaging is probably the major contributor to a
reduction in mortality for certain cancers. Targeted imaging ofreceptors, gene therapy
expression and cancer stem cells are research activities that will translate into clinical use
in the next decade. Technological developments will increase imaging speed to match
that of physiological processes. Targeted imaging and. therapeutic agents will be
developed in tandem through close collaboration between academia
biotechnology, information technology and pharmaceutical industries.
21. What is the role of Screening in cancer treatment?
Answer:
Sereening asymptom-jreepopulation
Disease discovery only occurs in a small number ofpeople.
Screening examinations are tests that are performed on a large group of symptom-free
people who may have an undetected disease. The goal ofscreening exams is to discover a
disease at an early stage so that it can be successfully treated.
[MODEL QUESTION]
Characteristics of the population must be defined:
The benefits ofearly discovery must outweigh the potential health consequences
of radiation exposure to the large number of people who donot have the disease.
A
screening program must identify the population at risk for the undetected disease.
By age
[MODEL QUESTION]
By gender
and
Byother factors, likeethnicity or family history of the disease

6. 27.What is staging of cancer? [MODEL QUESTION]
After diagnosis, the extent of tumour spread (tumour stage) must be determined as
accurately as possible; it has implications on optimal management and allows for
prognostication. A standardised system aids in communication, standardisation of
treatment and allows for consistency in reporting ofdisease outcomes.
Answer:
There are several staging systems used in oncology. The most frequently used one is the
TNM ((Tumour, Node, Metastasis) system maintained by the Union for International
Cancer Control (UICC).

7. 34.How is cancer treated?
Answer:
Treatment options depend on the type of cancer, its stage, if the cancer has spread and
your general health. The goal of treatment is to kill as many cancerous cells while
reducing damage to normal cells nearby. Advances in technology make this possible.
The three main treatments are:
Surgery: directly removing the tumor
[MODEL QUESTION]
Chemotherapy: using chemicals to killcancer cells
Radiation therapy: using X-rays to kill cancer cells
The same cancer type in one individual is very different from that cancer in another
individual, Within a single type of cancer, such as breast cancer, researchers are
discovering subtypes that each requires adifferent treatment approach.

8. 27.What is staging of cancer?
Answer:
After diagnosis, the extent of tumour spread (tumour stage) must be deermined as
accurately as possible; it has implications on optimal management and allows for
prognostication. A standardised system aids in communication, standardisation of
treatment and allows for consistency in reporting ofdisease outcomes.
There are several staging systems used in oncology.The most frequently used one 1S the
TNM (Tumour, Node, Metastasis) system maintained by the Union for International
Cancer Control (UICC).
28.What is the TNM stagingsystem?
Answer:
[MODEL QUESTION]
This divides the elements of tumour spread into three categories: extent of tumour
invasion (T), involvement of regional lymph nodes (N), and distant haematogenous
metastases (M).
T
The definition of T.N and M differsfor each disease site. The principles are below:
N
M
[MODEL QUESTION]
cannot be assessed occult (no primary tumour evident) in situ (i.e. non invasive)
increasing T stage implies increasing size and/or degree of invasion into the organ
or surrounding tissues.
tumour.
cannot be assessed node negative N stage increases with increasing number of
nodes, presence of large or matted nodes,or nodes more distant from the primary
no metastases metastaticdisease present (usually implying haematogenous spread)