Reader beware--medicine and biology are way outside my wheelhouse, and it's been some time since I've read this book.
If you've known someone with cancer, there's a good chance that the treatment consisted of some combination of chemotherapy, radiation, and surgery. In a sense these are very brute force ways to treat the problem, and as you might have noticed that the collateral damage can be massive. For the most part, the brute force approach to treating cancer comes to us from an empirical (actually experimental) tradition.
For a long time, surgery was the preferred method of treating cancer. The tricky thing is that simply cutting out a visible tumor doesn't always eliminate cancer from the body. This fact, discovered empirically, led to improvements in surgical technique but also to some extreme practices among some doctors. William Halsted performed "radical mastectomies" which left breast cancer patients with severed collarbones and gaping holes in their bodies. "Halsted and his disciples would rather evacuate the contents of the body than be faced with cancer recurrences" (65). This was part of a broader milieu in the world of surgery. "By 1898, it had transformed into a profession booming with self-confidence" (66).
Over the short term, these extreme surgical methods seemed to work reasonably well. But they reflected a woefully incomplete understanding of cancer. They could often cure the problem in women with small, local cancer activity, but at the cost of destroying the body without cause. On the other hand, cancer that had metasticized throught the body was not eliminated with the surgery. The approach did not save nearly as many lives as its proponents hoped, and it left a lot of people tragically disfigured.
Radiation was a more precise approach allowing specific targets (see page 75). It could often work well for localized tumors, saving many lives. Sometimes, though, it could actually cause cancer. And in any case, the collateral damage can still be huge, leaving patients "scarred, blinded, and scalded." It destroys cells indiscriminately.
Chemotherapy has roots in experiments with cloth dyes in the 1800s (85) and mustard gas in WWI (87). In the 1940s, treatments with combinations of chemicals were employed in increasingly well-designed experiments. This is chemotherapy, and while it's more advanced than surgery it is similar in that it employs brute force methods with huge collateral damage. Its advancement was driven by experiment rather than a growing understanding of cancer. Treating each specific cancer was just a matter of finding the right combination of toxins. The approach could lengthen lives, but sometimes by only a few months (208) (and sometimes for much longer!). Collateral damage was often huge. Much of cancer research funding went toward these experiments as opposed to deeper research:
They wanted a Manhattan Project for cancer. Increasingly, they felt that it was no longer necessary to wait for fundamental questions about cancer to be solved before launching an all-out attack on the problem (121).
This approach had some success in treating cancer, with high costs (page 330 reviews cancer treatment's results to the mid-1980s). So there was some backlash:
As the armada of cytotoxic therapy readied itself for even more aggressive battles against cancer, a few dissenting voices began to be heard along its peripheries. These voices were connected by two common themes.
First, the dissidents argued that indiscriminate chemotherapy, the unloading of barrel after barrel of poisonous drugs, could not be the only strategy by which to attack cancer. Contrary to prevailing dogma, cancer cells possessed unique and specific vulnerabilities that rendered them particularly sensitive to certain chemicals that had little impact on normal cells.
Second, such chemicals could only be discovered by uncovering the deep biology of every cancer cell. Cancer-specific therapies existed, but they could only be known from the bottom up, i.e., from solving the basic biological riddles of each form of cancer, rather than from the top down, by maximizing cytotoxic chemotherapy or by discovering cellular poisons empirically.
This biology-based approach gained some traction, and there were some major breakthroughs in the 1980s that identified cancer-causing mechanisms at the molecular level. There has been a lot of progress since then. Understanding cancer better has made us better at early detection, which has significantly reduced mortality. More chemotherapy has played a role too. One cancer researcher looks back at a pioneer of experimental cancer treatment, Sidney Farber (from the 1940s), and writes,
Farber's generation had tried to target cancer cells empirically, but had failed because the mechanistic understanding of cancer was so poor. Farber had had the right idea, but at the wrong time. (433)
The author concludes that "an integrated approach" is needed (457). The case of breast cancer is particularly illustrative of this point (402).
So basically we spent a century treating cancer with methods discovered through experiment, with results that range from tragic to pretty good (the book reviews some studies). In a sense the approach served us pretty well, providing ways to treat a terrible disease without having to invest a lot of time and money in knowing a lot about it. Then we focused more on understanding the disease, which gave us pretty good progress. At any given point in time, focusing more on basic research may have denied effective treatment to existing patients, but it may have sped the process of finding better approaches.
I don't really have any big conclusions other than to say that I think the conflict between theory and empirics is complicated and may be unavoidable, particularly in the case of economics. The "credibility revolution" is a huge step forward for the field with its ability to provide quick answers to policy questions. But what does it tell us about a $15 minimum wage? Nothing, really. But theory is a messier business, and it can result in a lot of wasted effort. So neither the theorists or the empiricists are in a position to feel overly important. We need both, and sometimes one will make progress faster than the other.
This book is a really good read with a lot of other insights relevant to economics (page 211 rings a bell, for example); recommended.