progressed compared with dacarbazine for patients whose
tumors could not be surgically removed or had advanced
disease and who had been previously treated with an
anthracycline-containing chemotherapy regimen ( 133).
This approval is providing new hope to patients like Nancy
McGuire (see p. 68).
Working Together to Treat Colorectal Cancer
Although screening for colorectal cancer has helped lower
U.S. colorectal cancer incidence and mortality rates ( 113)
(see Increasing Options for Colorectal Cancer Screening, p.
57), the disease remains the second leading cause of cancer-
related death in the United States ( 3). In September 2015, the
FDA provided fresh hope for patients with the disease when
it approved a ne w treatment option for advanced colorectal
cancer that is no longer responding to other treatments: a
combination of drugs formulated together in a single tablet
called Lonsurf (previously known as TAS- 102).
The two therapeutics in TAS- 102—trifluridine and
tipiracil—work together to target colorectal cancer.
Trifluridine is a cytotoxic chemotherapeutic that causes
damage to DNA in the rapidly multiplying cancer cells,
which can ultimately trigger cell death; tipiracil prevents
rapid breakdown of trifluridine, thereby maintaining
adequate levels of trifluridine in the body.
Trifluridine damages DNA in a similar way to the cytotoxic
chemotherapeutic fluorouracil, which has been used as
a treatment for colorectal cancer for decades. However,
in the phase III clinical trial that led to the FDA approval
of TAS- 102, the new combination chemotherapy tablet
improved survival compared with placebo even for those
patients who had colorectal cancer that was no longer
responding to treatment with fluorouracil-containing
chemotherapy regimens ( 135).
Treatment With Molecularly
Research is powering the field of precision medicine in
many ways, including by increasing our understanding
of the genetic, molecular, and cellular changes that lead
to cancer initiation and development. Therapeutics
directed to the molecules involved in different stages of
the cancer process target the cells within a tumor more
precisely than cytotoxic chemotherapeutics. The greater
precision of these molecularly targeted therapeutics tends
to make them more effective and less toxic than cytotoxic
chemotherapeutics. As a result, they are not only saving the
lives of countless patients with cancer, but also allowing
these individuals to have a higher quality of life.
is a synthetically produced
version of a natural product
isolated from the marine sponge
Halichondria okadai and
is a modified version of a
natural product from the sea
squirt Ecteinascidia turbinata,
highlighting the utility of natural
Estimated New Colorectal Cancer Cases
Estimated New Colorectal Cancer Deaths