Transcript Neoplasia part II - Dr. Mohsen Dashti
Neoplasia part II
By
Dr. Mohsen Dashti Clinical Medicine & Pathology
3 rd lecture
Lecture outline
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Diagnosis of cancer.
Symptoms of cancer.
Cancer therapy.
Diagnosis of cancer
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Is visual examination enough for diagnosing cancer?
- Off course not. Final diagnosis of cancer requires medical laboratory tests.
- Laboratory tests can be done in number of methods: -
1. Biopsy.
Following a surgical operation the tumor is sent to the laboratory to check whether or not the lesion is malignant.
In some cases, particularly breast cancer, the surgeon might ask for a “quick” report on the nature of the lesion while the patient is still under the knife so appropriate action can be taken.
The report bares extreme responsibility since surgeons depend heavily on its outcome.
Diagnosis of cancer
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2. Exfoliative cytology.
Casting or shedding cells from the body surface since cancer cells tend to lose adhesiveness characteristic of normal cells.
Although this method is loosely inaccurate, it opened doors for early diagnosis.
It is routinely used in vaginal testing and considered the early method of smear test.
3. Fine needle aspiration cytology.
Small cell clumps are aspirated through a long needle attached to a syringe to obtained cells deeply located organs. Example?
Thyroid gland, lymph nodes, or pancreas.
Diagnosis of cancer
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4. Chemical tests.
It is an ultimate dream to come up with some sort of chemical tests for the diagnosis of cancer without the need for previously mentioned methods. Do dreams come true?
Some of them do. Example?
Some tests may be of clinical value, as in carcinoma of the prostate, in which increased acid phosphatase levels suggests that diagnosis.
The production of alpha-fetoprotein by the abnormal cells of the liver can indicate cancerous cells and may be detected chemically.
CEA or carcinoembryonic antigen can also be detected chemically to indicate cancer of the large bowel.
Diagnosis of cancer
Symptoms of cancer
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How painful is cancer in the early stages?
- Not painful at all and that’s a major problem. Why?
- If it were as painful as toothache, far fewer people would die from the disease.
- So what are the general symptoms of cancer?
- Weakness, loss of weight, anemia, and pain late in the disease. Do they differ in various region of the body? - Yes. Example?
1. Lip or breast, a lump may be felt.
2. If the affected organ communicates with the surface, there may be a discharge or bleeding as in cancer of the uterus.
3. Lost of appetite as in cancer of the stomach.
4. Blood in the urine as in cancer of the kidneys.
Symptoms of cancer
- It should be noted that a malignant tumor of some size may be discovered incidentally at autopsy and may not present any pain.
- It must be remembered that the symptoms may not be due to the primary tumor, which may remain latent, but due to metastases. Example?
- A silent carcinoma of the lung that metastasizes to the brain, so that the patient comes to the doctor with symptoms of brain tumor, but no cough, shortness of breath, pain in the chest, or spitting of blood.
Symptoms of cancer
Symptoms of cancer
- The previously mentioned symptoms are considered clinical effects of cancer due to a local lesion or metastases; however, there are other symptoms known as systemic manifestations.
- These include; various inflammation of the skin, vascular effects, hormonal disturbances, and neuromuscular symptoms suggesting lesions of the nerves and muscles.
Cancer therapy
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What are the common ways in cancer therapy?
1. Surgical removal.
2. Radiotherapy.
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3. Chemotherapy.
It should be clearly understood that malignant cancer can not be cured entirely especially if it metastasizes.
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1. Surgical removal:
Innocent tumors (benign) are treated with complete success by local removal, that is to say, only the tumor itself needs to be removed and none of the surrounding tissue. How about malignant tumors?
With malignant tumors not only the tumor is removed, but also as much as is feasible of the surrounding tissue as well.
Cancer therapy
- In some cases and depending on the part of the body affected, the regional lymph nodes also may have to be removed.
- The removal of the lymph nodes may not be necessary in all malignant tumors and depends on the regional location.
- A good example is with breast cancer compared to a lip cancer where the latter doesn’t require lymph nodes removal.
2. Radiotherapy:
How can radiation differentiate between cancer and non cancer cells in radiotherapy?
Radiations have a greater destructive action on rapidly growing cells than on normal cells, therefore they have a selective action on cancer cells compared with that on surrounding tissue.
Cancer therapy
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Does radiotherapy require special skills & how does it work?
- Yes it does.
- Either gamma rays or x-rays are used in radiation therapy.
- X-rays may be generated by low voltage (50,000 to 100,000 volts) or high voltage (220,000 + volts). The low voltage rays are known as soft, whereas the higher voltage rays called hard.
- Soft rays have light penetration power and mainly suitable for surface tumors.
- Hard rays have higher penetration power and suitable for deep-seated tumors.
Cancer therapy
- It should be clearly understood that understanding tumor pathology and its associated manifestations is extremely important prior to any radiotherapy plan.
- Some tumors are highly radiosensitive, whereas others are highly radioresistant.
- Radiation therapy is employed in the treatment of localized neoplastic lesions that are not surgically accessible or in situations where surgery would be impractical.
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3. Chemotherapy:
It employs a wide variety of powerful metabolic inhibitors and other cell-killing chemicals that are often used on various combinations for treatment of different cancers.
They work on cancer cells in a similar way that radiations do.
Cancer therapy
- Chemotherapy has been most successful for certain types of leukemias and lymphomas.
- Other treatment options in cancer therapy include; hormonal therapy used in breast and prostate cancers, and protein therapy that kills selective cells.