The surfit function shows details for different genders. If we look at the first observation, where sex=1 (Male), it states that a total of 138 males were in the cancer dataset, of which 112 people died; the median time is 270 days. It also points out that the 95% confidence interval for the median survival time for 212 is 310.
The summary of the survfit function displays the data in a tabular format for each time point in the dataset. At every step, it computes the total person at risk; that is, n.risk, the number of events at a given time point, and n.point: proportion who survived at a point of time with the standard error and confidence level. If we look at the first two lines of output:
time n.risk n.event survival std.err lower 95% CI upper 95% CI
11 138 3 0.9783 0.0124 0.9542 1.000
12 135 1 0.9710 0.0143 0.9434 0.999
We can see that at time 11, in our case the time is in days, so on the 11th day, the total number of people at risk was 138, out of which an event occurred for 3; that is, three people died.
On the 12th day, the total number of people at risk was 138 - 3 = 135, of which one person died.
It also shows the standard error, and the upper and lower confidence of the curve.