The author of the article speculates that this reluctance is due to convenience and careerism, specifically the fear of having others (especially layfolk) analyze their work and possibly find flaws in it. This may be an uncharitable speculation but it is difficult to disagree with, especially when one considers the pathetic reasons scientists cite for hiding their data. From the article:
Dr John Kirwan, a rheumatologist from the University of Bristol in England, has studied researchers’ attitudes on sharing data from clinical trials. He found that three-quarters of researchers he surveyed, as well as a major industry group, opposed making original trial data available. It is worth restating this finding: most scientists doing research on how best to help those in pain, or at risk of death, want to keep their data a secret.
Dr. Kirwan went on to ask his subjects why. Their reasons were entirely trivial: one cited the difficult of putting together a data set (wouldn’t this have to be done anyway in order to publish a paper?); another was concerned that the data might be analyzed using invalid methods (surely a judgment for the scientific community as a whole). This is something of a clue that the real issue here has more to do with status and career than with any loftier considerations. Scientists don’t want to be scooped by their own data, or have someone else challenge their conclusions with a new analysis.
As the author points out, however, new analyses are exactly what cancer patients (and patients in general) need. We all need all the information available that pertains to our health, so we can look at it and think about it and use it to safeguard ourselves. This reluctance to part with information is contrary to the spirit of scientific openness and inquiry. It is also unsafe and unfair to patients.