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29 Mar 2018

A spherical tumor 3 cm in diameter consisting of prostate cells may result in a PSA blood level of about 20 nanograms/milliliter of blood. The test can only detect the presence of PSA in the blood if it is greater than about 0.1 ng/ml. An MRI can detect a cancerous tumor down to about a diameter of 1 mm. Which is a more sensitive test for the return of prostate cancer, the blood test or an MRI? To decide this, estimate how big a tumor could be and still produce a PSA level less than 0.1 ng/ml. diameter <__________ mm

Would a tumor that produced this (undetectable) amount of PSA be visible on an MRI? No or Yes Which test would be able to see the smaller tumor? The MRI scan or The PSA blood test Explain your reasoning.

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Hubert KochLv2

30 Mar 2018

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PSA is a screening test used to detect patients who may be at a higher risk of developing prostate cancer. A PSA value > 4.0 ng/mL is typically a value that physicians would use to further recommend a prostate biopsy. Statistics show that only 25% of men with a PSA > 4.0 actually have prostate cancer. The cost of a prostate biopsy is expensive but the cost of missing a case could be fatal.

a. Based on the above information, what factors would you consider when recommending a PSA screening test to a patient? Would you err on the side of having a false positive or false negative? Explain your rationale.

b. Based on the above information, what is the false positive rate for a PSA test?

c. Suppose you sample 35 men with prostate cancer and 35 without prostate cancer. Among the 35 with prostate cancer, 7 have a PSA > 4.0. Among the 35 without prostate cancer, 3 have a PSA greater than 4.0. Based on this data, calculate the sensitivity, specificity, positive predictive value and negative predictive value. HINT â It may be helpful to draw out the 2 by 2 grid. Show calculations

violetpug108

A 67-year-old retired male went to his doctor, complaining initially of leg pain that started in his lower back, which then radiated down across the side of his thigh and over the front of his knee. Subsequently, he developed pain that radiated from his back to his front at two different levels: at the chest through the level of his nipples and also at the umbilicus.

His physician performed a history and physical, followed by laboratory tests. He discovered a hard nodule on his prostate and an elevation in several of the blood tests. His PSA (prostate specific antigen), an enzyme secreted by normal prostate tissue (0-4 ng/ml) was 450. Alkaline phosphatase was also elevated at 157 U/L, an indication of bone involvement.

A bone scan was ordered to visualize the bone involvement. (This test uses a calcium analogue attached to a radioactive tag. A special scanner can pick up images of this radioactivity and create an anatomical picture of the skeletal system. The radiation shows up as black spots on the film.)

Usually prostate cancer's growth is initially influenced by the presence of testosterone. If testosterone is removed by castration, the cancer will often shrink for some period of time before the remaining fraction of testosterone-independent cancer cells grow.

This gentleman was not interested in castration and asked if there was another way to treat this. He was treated was a single shot of a drug which is slowly released into the body over a three month time period. Within that time the patient noticed marked relief in his pain.

1. What is the diagnosis of this gentleman?

2. Why would the scan show bone abnormalities?

3. Which endocrine organs are responsible for serum calcium levels?

4. Describe the feedback loop between the anterior pituitary and the production of testosterone in the testes.

5. Describe a mechanism by which a drug could act on the anterior pituitary to lower the testosterone level in the human body.

coppershark967

61) How areantiangiogenic drugs used in the treatment of

cancer?

A) These drugsstop the replication of DNA so cancer cells

cannot reproduce.

B) These drugsstop the growth of blood vessels into the

tumor, so the cells "starve" to death.

C) These drugsstop metastasis.

D) These drugsstimulate the immune system.

E) These drugsstimulate the production of free radicals,

which kill cancer cells.

62) Which of the

following is true regarding photodynamic therapy?

A) It involves the use

of light sensitive drugs to target a cancer.

B) It uses magnets to

attract beads coated with a chemotherapeutic drug to acancer.

C) It is presently used

for the treatment of cancers of the breast and ovary.

D) It inhibits

angiogenesis.

E) It involves the use

of antibodies to deliver treatments to a cancer.

63) Which ofthe following types of cancer kills the highest

percentage of people diagnosed with the condition?

A)lung

B)breast

C)prostate

D)skin

E)colon

64) A mutationin which of the following genes can lead to

breast cancer?

A) BT05

B) HeLa

C) BRCA1

D)BCG

E)BCG2

65) If angiogenesis

were not to occur, a tumor would reach the size of a ________and stop growing.

A) period on a

typewritten page (.)

B) baseball

C) grapefruit

D) pea

E) basketball

66) Not onlydoes smoking cause lung cancer, it also doubles

the risk of which of the following types of cancer?

A)stomach

B)prostate

C)bladder

67) For women with a

mutated BRCA gene, the risk of breast cancer is about 60%.However, detection

of the mutated gene can occur before cancer ever develops by

A) testing of a blood

sample.

B) screening

mammography.

C) taking a biopsy of

breast tissue.

D) a PET scan.

E) urinalysis.

68) In some cases, why

doesn%u2019t the immune system recognize and destroy acancer?

A) Cancer cells that

produce abnormal antigens sometimes shed them.

B) Cancer cells have

less surface receptors needed for proper activation of Tcells.

C) Cancer cells have

enough %u201Cself%u201D surface markers as to be identified asnormal cells.

D) Cancer cells develop

from normal cells that cannot regulate cell division.

E) all of the above are

correct.

69) Theultimate goal of the male reproductive system is to

A) ensure thatsperm is produced at the correct time,

coinciding with ovulation.

B) releasesperm into the female's reproductive system.

C) join spermwith an egg, in an environment that favors

fertilization.

D) producelarge numbers of sperm.

E) maintain thehomeostatic condition of the male's body.

70) Synthesisof new sperm cells occurs in the

A) ductusdeferens.

B)urethra.

C) prostategland.

D) epididymis.

E) seminiferous tubules.

71) Externalgenitalia

of the male reproductive system include(s)

A) theejaculatory duct.

B) the urethraand scrotum.

C) the penisand scrotum.

D) thepenis.

E) the penis,urethra, and ejaculatory duct.

72) The releaseof LH in human males signals that

A) inhibin hasinhibited FHS secretion.

B) thehypothalamus has been stimulated to release inhibin.

C) spermproduction must be reduced.

D) the positivefeedback loop that regulates sperm production

is active.

E) blood levels of

testosterone are low

emeraldjellyfish291

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