Question

Metastasis is responsible for about 90% of cancer associated deaths. The five year survival rate comparisons for metastatic and non-metastatic tumors in various tissues was presented in lecture 10. The prostate cancer survival rate for non-metastatic tumors is 100%, whereas for liver cancer it is 28%. Why do you think there is such a big difference in survival rates for these two cancer types when both are non-metastatic tumors? (5 points)

Answer 1

Non- metastatic tumor means that the tumor is localized to the affected organ.

Liver is the largest gland of our body , having numerous vital functions.

1. It produces bile which helps in digestion , emulsification of the fats.

2. It stores glucose as glycogen which provides us with nourishment during fasting or / and during starvation.

3. It breaks down medications, toxins and forms urea that is later excreted through kidneys.

4.It helps in formation of plasma proteins ,clotting factors and synthesis of heparin (natural anticoagulant).

5.It purifies blood with the help of Kupffer cells ( hepatic tissue macrophages ).

6. It helps in synthesis of Vitamins A,D,E,K and B12

7. It stores iron , Cobalt, zinc , copper , molybdenum, etc.

A tumor involving liver will cause derangement in all its functions including improper digestion and metabolism , hypoproteinemia , easy bruising and bleeding , accumulation of toxins in the body, vitamin deficiency , etc. These impairments will eventually decrease the prognosis and the survival .

Further the recurrence rate after resection is high especially in micro and macro vascular infiltration and presence of cirrhosis.

Prostate on the other hand is non-vital organ present in males.

It secretes prostatic secretions that nourish the sperms , and forms semen. It also prevents passage of urine during coitus.

A localized tumor (non- metastatic ) will cause problems in urination , incontinence , blood in urine / semen , erectile dysfunction. It has no direct effects on body metabolism and vital functions. Also Tumor recurrence rate after removal of prostate is less as compared to liver tumor.

Hence as seen above since liver carriers out various important functions for the body ,any non- metastatic tumor will have poor prognosis as compared to that of prostatic tumor.

I don't know what has been taught in your lecture 10. I hope this much information is enough for your question.

For any clarifications please drop a note in comment section.