Read the following paragraph and underline the topic sentences.
Surviving Cancer
Progress is gradually being made in the fight against cancer. In the' early 1900s, few cancer patients had any hope of long-term survival. In the 1930s, less than one in five cancer victims lived more than five years. In the 1950s, the ratio was one in four, and in the 1960s, it was one in three. Currently, four of ten patients who get cancer this year will be alive five years from now. The gain from one in four to four in ten represents about 69 ,000 lives saved each year.