Journalist: More and more people are being diagnosed with thyroid cancer. Many doctors have long believed that this is solely...
GMAT Critical Reasoning : (CR) Questions
Journalist: More and more people are being diagnosed with thyroid cancer. Many doctors have long believed that this is solely due to unnecessary testing that finds small tumors that do not lead to complications. However, while greater awareness of this cancer, especially its tendency to strike younger women, has indeed prompted more-frequent testing, overtesting is not really the culprit, because
Which of the following most logically completes the passage?
Passage Analysis:
| Text from Passage | Analysis |
| More and more people are being diagnosed with thyroid cancer. |
|
| Many doctors have long believed that this is solely due to unnecessary testing that finds small tumors that do not lead to complications. |
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| However, while greater awareness of this cancer, especially its tendency to strike younger women, has indeed prompted more-frequent testing, overtesting is not really the culprit, because |
|
Argument Flow:
"We start with an observed trend (rising thyroid cancer diagnoses), then get the standard medical explanation (overtesting finds harmless tumors), and finally the journalist challenges this explanation while acknowledging testing has increased. The argument is incomplete and waiting for evidence to support why overtesting isn't the real culprit."
Main Conclusion:
"Overtesting is not the real reason for increased thyroid cancer diagnoses (though the argument is incomplete and needs supporting evidence)"
Logical Structure:
"The journalist uses a 'challenge the conventional wisdom' structure - acknowledging the standard explanation has some merit (testing did increase) but arguing it's not the complete answer. The 'because' at the end signals we need evidence that will show why the overtesting explanation falls short."
Prethinking:
Question type:
Logically Completes - We need to find a statement that provides evidence against the 'overtesting explanation' for increased thyroid cancer diagnoses
Precision of Claims
The key claims are about causation (what's really causing increased diagnoses) and the nature of the tumors being found (small harmless ones vs. something else)
Strategy
The journalist accepts that testing has increased but argues overtesting isn't the real culprit. We need evidence that shows the increased diagnoses aren't just from finding more small, harmless tumors. This could be: (1) evidence that larger, more serious tumors are being found, (2) evidence that the increase in diagnoses reflects real disease increase, not just detection, or (3) evidence that contradicts the 'small harmless tumors' characterization
'exposure to certain chemicals appears to be associated with thyroid cancer' - While this could explain why thyroid cancer is increasing, it doesn't directly address the journalist's argument about why overtesting isn't the real culprit. The journalist needs evidence that specifically counters the 'small harmless tumors' explanation, not just a general cause of cancer.
'patients do not usually have symptoms unless the cancer is at an advanced stage' - This actually supports the doctors' view that testing finds tumors before symptoms appear, which could include many small, harmless ones. This doesn't help the journalist's argument against overtesting being the culprit.
'the accuracy of diagnostic tests for thyroid cancer has not increased significantly' - This is irrelevant to the central debate. Whether tests are more or less accurate doesn't address whether increased testing is finding mainly harmless small tumors or if there's a real increase in meaningful cancers.
'the survival rate for thyroid cancer is higher than it is for most other cancers' - This information about survival rates doesn't address the core issue of whether increased diagnoses come from overtesting small harmless tumors versus a real increase in significant cancers.
'thyroid tumors of all sizes are increasing significantly in number' - CORRECT. This directly undermines the doctors' explanation that increased diagnoses come from finding small, harmless tumors through overtesting. If tumors of ALL sizes are increasing, this suggests a genuine increase in the disease itself, not just better detection of small, insignificant tumors. This perfectly supports why overtesting isn't the real culprit - because we're seeing more cancers across the board, not just more detection of small ones.