Cancer has been a boon to Showtime’s health.

Pay cabler has picked up a second season of Laura Linney half-hour dramedy “The Big C,” as well as a seventh season of “Weeds.”

“The Big C” premiered Aug. 16 and the pilot drew 1.6 million for its initial showing — the highest for a Showtime premiere in eight years. When including multiple telecasts, DVR usage and video on demand, the total jumped to more than 6 million. “Weeds,” which followed “The Big C,” drew 2 million on the same night.

Linney, who co-stars with Oliver Platt, Phyllis Somerville and Gabourey Sidibe as a mom facing a stage four melanoma diagnosis, is exec producer along with creator Darlene Hunt, Jenny Bicks, Vivian Cannon and Neal H. Moritz. Skein is produced by Sony Pictures Television.

Lionsgate TV-produced “Weeds” has been a Showtime staple since 2005. The Mary-Louise Parker starrer was the first of the net’s dramedies to examine moms dealing with difficult personal issues.

In addition to “The Big C” and “Weeds,” Toni Collette struggles with multiple personality disorder in “United States of Tara” and Edie Falco has a drug addiction in “Nurse Jackie.”

New seasons of “The Big C” and “Weeds” will launch in 2011. “Weeds” is exec produced by Jenji Kohan, Roberto Benabib and Matthew Salsberg.

This marks the first series renewals by Showtime topper David Nevins, who replaced Robert Greenblatt in July.