Name______Section______Date______

Lesson 1.1 Worksheet

In 2009 a CAT scan detected a tumor approximately 10 mm in diameter (523 mm3 in volume) in Steve Jobs’ pancreas. Given that a pancreatic cell is approximately 0.01 mm in diameter (5.23 x10-7 mm3 in volume); we can calculate that the tumor contained approximately 1 x 109 cells.

How many doublings would it take for one cell to grow a detectable tumor – that is, a tumor that contains 1 x 109 cells? Let’s look at the following table:

Number Number Number Number of of of of Doublings # of Cells Doublings # of Cells Doublings # of Cells Doublings # of Cells 2,147,483,64 1 2 11 2,048 21 2,097,152 31 8 4,294,967,29 2 4 12 4,096 22 4,194,304 32 6 8,589,934,59 3 8 13 8,192 23 8,388,608 33 2 17,179,869,1 4 16 14 16,384 24 16,777,216 34 84 34,359,738,3 5 32 15 32,768 25 33,554,432 35 68 68,719,476,7 6 64 16 65,536 26 67,108,864 36 36 137,438,953, 7 128 17 131,072 27 134,217,728 37 472 274,877,906, 8 256 18 262,144 28 268,435,456 38 944 549,755,813, 9 512 19 524,288 29 536,870,912 39 888 1,099,511,62 10 1,024 20 1,048,576 30 1,073,741,824 40 7,776

Slow-growing pancreatic tumors, like the tumor that Steve Jobs had, double in size once every 10 months. Therefore, Steve Jobs tumor doubled its number of cells every 10 months (Doubling Rate). We can calculate how long it took for the tumor to be detectable using the formula:

CALCULATION: Number of Doublings * Doubling Rate = Time to Grow (months)

From the table, it takes about 30 doublings to get to 1 x 109 cells from 1 cell.

30 * 10 = 300 = Time to grow tumor (months) 300/12 months in a year = 25 years = Time to grow tumor (years)

1. Since Steve Jobs was only diagnosed with a pancreatic tumor at the age of 48, how old was he when the original pancreatic tumor started forming? Name______Section______Date______

2. But Steve Jobs’ pancreatic cancer didn’t kill him! Instead, when he was having it removed, his surgeons found that his primary cancer had metastasized to form a secondary cancer in his liver. If a liver tumor must be 10 mm in diameter and contain 1 x 109 cells to be detectable, how many doublings were necessary to form this secondary tumor?

3. Metastasizing tumors double faster than primary tumors – once every 8 months. How long would it take for one tumor cell to form a detectable (10 mm in diameter) secondary tumor in the liver?

4. How old was Steve Jobs when the pancreatic tumor spread to the liver if the liver tumor was detected at age 49?

5. But Steve Jobs’ liver cancer didn’t kill him either! Instead, he died of respiratory failure from a lung tumor when he was 56. Lung tumors stop lung function (breathing) when they get above 100 mm in diameter (or 1 x 1012 cells). How many doublings does it take to get to that size?

6. Lung tumors are also metastases, so they also double every 8 months. How long did it take for this lung tumor to form from one metastatic pancreatic cell?

7. How old was Steve Jobs when the pancreatic tumor spread to the lungs?

8. Do you think that waiting 9 months to have surgery to remove his tumor cost Steve Jobs his life? Why or why not? Name______Section______Date______

9. Considering the fact that Steve Jobs died of respiratory failure (another tumor formed in his lungs and stopped lung function), which do you think is more important: the size that the original tumor reaches, or how quickly it spreads? Why?